Curable composition and process for producing cured film

ABSTRACT

A curable composition that is sufficiently cured even without a heating step at high temperature and from which a low dielectric constant cured film excellent in solvent resistance is obtained. A curable composition containing a fluorinated polyarylene prepolymer (A) having a crosslinkable functional group, a compound (B) having a number average molecular weight of from 140 to 5,000, having at least two crosslinkable functional groups and having no fluorine atoms, a copolymer (C) having the following units (c1) and (c2) and a radical polymerization initiator (D): unit (c1): a unit having a fluoroalkyl group having at most 20 carbon atoms, which may have an etheric oxygen atom between carbon atoms, and having no crosslinkable functional group; unit (c2): a unit having a crosslinkable functional group.

TECHNICAL FIELD

The present invention relates to a curable composition and a process forproducing a cured film by using the curable composition.

BACKGROUND ART

In the electronics filed, development of insulating materials having lowdielectric constants is advancing. For example, a polyarylene resin hasbeen proposed as an insulating material suitable for an interlayerinsulating film for semiconductor devices, a gate insulating film forthin-film transistors (TFT), a stress relaxation layer for aredistribution layer, etc. (Patent Document 1).

Further, a negative photosensitive resin composition has been proposedwherein a polyarylene resin has been provided with photosensitivity(Patent Document 2). With such photosensitivity, microfabrication byphotolithography becomes possible in the same manner as e.g. aphotoresist. For example, when an interlayer insulating film is formedby using a polyarylene resin having photosensitivity, there is such amerit that a contact hole can easily be formed in the interlayerinsulating film by photolithography without using a photoresist.

In recent years, various flexible devices attract attention. Forexample, for a TFT for a flexible display, an inexpensive resinsubstrate such as polyethylene terephthalate (PET) or polyethylenenaphthalate (PEN) is preferably used. However, as such a resin substratehas a heat resistant temperature of so low as from 150 to 200° C., it isnecessary to produce the TFT at low temperature so that the substrate ismaintained to the heat resistant temperature or below in the entireprocess.

Further, depending on the application, the surface of a cured film witha low dielectric constant is required to have liquid repellency in somecases. For example, in a case where a gate insulating film is formed bya low dielectric constant material and an organic semiconductor layer isprovided thereon, in order to increase the degree of orientation ofmolecules of the organic semiconductor to improve the electron mobility,the surface of the gate insulating film preferably has liquidrepellency.

The following Patent Document 3 discloses to add, as an ink repellent, acopolymer having units having a fluorine-substituted alkyl group andunits having an ethylenic double bond to a negative photosensitivecomposition containing a (meth)acrylic resin as the main component.

Further, the following Patent Document 4 discloses that in a method offorming a low dielectric constant insulating film or the like by using acurable composition containing a fluorinated polyarylene prepolymer bymeans of a heating step at 300° C. or above, by incorporating a compoundhaving a molecular weight of from 140 to 5,000, having a crosslinkablefunctional group and having no fluorine atoms in the curablecomposition, the flatness of the film surface is improved.

PRIOR ART DOCUMENTS Patent Documents

-   Patent Document 1: WO2003/008483-   Patent Document 2: WO2007/119384-   Patent Document 3: WO2004/042474-   Patent Document 4: WO2009/154254

DISCLOSURE OF INVENTION Technical Problem

With a conventional curable composition comprising a fluorinatedpolyarylene resin, a step of imparting an external energy such as heator light to a fluorinated prepolymer having a crosslinkable functionalgroup for crosslinking is necessary, and for sufficient curing, a curingstep at high temperature of at least 300° C. is necessary. If curing isinsufficient, for example, the solvent resistance of the obtainablecured film is insufficient, and when the cured film is brought intocontact with a solvent in a device production process, swelling orreduction in thickness of the cured film may occur. Accordingly, it hasbeen considered that a fluorinated polyarylene resin cannot be used fora low temperature process using a substrate having a low heat resistanttemperature.

Further, even if the heat resistant temperature of the substrate such asa silicon substrate is not low, in a case of forming a cured film on asubstrate having a large area, the substrate is likely to be warped whencured at high temperature.

Accordingly, a curable composition which is sufficiently cured evenwithout a heating step at high temperature, and which is capable offorming a cured film having a favorable solvent resistance, a lowdielectric constant and a favorable liquid repellency on the surface isdesired.

The present invention has been made under these circumstances, and itsobject is to provide a curable composition which is sufficiently curedeven without a heating step at high temperature, and which is capable offorming a cured film having an excellent solvent resistance, a lowdielectric constant and a favorable liquid repellency on the surface, aprocess for producing a cured film by using the curable composition, andan organic thin-film transistor using a cured film obtainable by curingthe curable composition.

Solution to Problem

The present invention provides the following [1] to [15].

[1] A curable composition comprising a fluorinated polyaryleneprepolymer (A) having a crosslinkable functional group, a compound (B)having a number average molecular weight of from 140 to 5,000, having atleast two crosslinkable functional groups and having no fluorine atoms,a copolymer (C) having the following units (c1) and (c2) and a radicalpolymerization initiator (D):

unit (c1): a unit having a fluoroalkyl group having at most 20 carbonatoms, which may have an etheric oxygen atom between carbon atoms, andhaving no crosslinkable functional group;

unit (c2): a unit having a crosslinkable functional group.

[2] The curable composition according to [1], wherein each of thecrosslinkable functional groups in the prepolymer (A), the compound (B)and the compound (C) which are independent of one another, is acrosslinkable functional group selected from the group consisting of avinyl group, an allyl group, an ethynyl group, a vinyloxy group, anallyloxy group, an acryloyl group, an acryloyloxy group, a methacryloylgroup and a methacryloyloxy group.[3] The curable composition according to [1] or [2], which contains from10 to 80 parts by mass of the compound (B) based on the total amount(100 parts by mass) of the prepolymer (A) and the compound (B).[4] The curable composition according to any one of [1] to [3], whereinthe radical polymerization initiator (D) is a thermal initiator or aphotoinitiator.[5] The curable composition according to any one of [1] to [4], whichcontains from 0.1 to 20 parts by mass of the copolymer (C) based on thetotal amount (100 parts by mass) of the prepolymer (A) and the compound(B).[6] The curable composition according to any one of [1] to [5], whereinthe unit (c1) is a unit formed by polymerization of a monomerrepresented by the following formula (4):V-Q-R—Cf  (4)

wherein V: a polymerizable group,

Q: a single bond or a bivalent organic group,

Cf: a fluoroalkyl group having at most 20 carbon atoms, which may havean etheric oxygen atom between carbon atoms, and

R: a single bond or a bivalent organic group.

[7] The curable composition according to [6], wherein the unit (c1) is aunit formed by polymerization of a monomer represented by the followingformula (5):V—(CH₂)_(m)—Ar—(Y—Ar)_(n)—X—R¹—Cf  (5)

wherein V: a polymerizable group,

Ar: an aromatic ring which may have a C₁₋₁₅ alkyl group or a halogenatom,

R¹: a single bond or a C₁₋₁₅ alkylene group,

Cf: a fluoroalkyl group having at most 20 carbon atoms, which may havean etheric oxygen atom between carbon atoms,

X: —CH₂O— or —COO—

Y: a single bond, —OCH₂—, —CH₂O—, a C₁₋₄ alkylene group, —O—, —OCH₂—,—CO—, —SO₂— or —S—,

m: an integer of from 0 to 4, and

n: 0 or 1.

[8] A coating composition comprising the curable composition as definedin any one of [1] to [7] and a solvent.

[9] A process for producing a curable composition, which comprises

reacting a fluorinated aromatic compound, a phenol compound and acrosslinkable functional group-containing organic compound in thepresence of a dehydrohalogenating agent to produce a fluorinatedpolyarylene prepolymer (A) having a crosslinkable functional group, and

mixing the above prepolymer (A), a compound (B) having a number averagemolecular weight of from 140 to 5,000, having at least two crosslinkablefunctional groups and having no fluorine atoms, a copolymer (C) havingthe following units (c1) and units (c2) and a radical polymerizationinitiator (D):

unit (c1): a unit having an alkyl group having at most 20 carbon atoms(which may contain an etheric oxygen atom), having at least one ofhydrogen atoms being substituted by a fluorine atom, and having nocrosslinkable functional group;

unit (c2): a unit having a crosslinkable functional group.

[10] A process for producing a cured film, which comprises forming afilm of the coating composition as defined in [8] on a substrate, andthermally curing or photo-curing the curable composition by a stepincluding one or more heating steps to produce a cured film, wherein theheating temperature in all the heating steps is at most 250° C.[11] A substrate having a cured film of the curable composition asdefined in any one of [1] to [7].[12] A method for treating a cured film, which comprises irradiating acured film of the curable composition as defined in [7] with light tolower the liquid repellency at a light-irradiated portion.[13] An organic thin-film transistor having a cured film obtained bycuring a film of the curable composition as defined in any one of [1] to[7] as a functional film.[14] The organic thin-film transistor according to [13], wherein thefunctional film is a gate insulating film.[15] A non-adhesion imparting agent comprising a copolymer having unitsformed by polymerization of a monomer represented by the followingformula (5) and units having a crosslinkable functional group:V—(CH₂)_(m)—Ar—(Y—Ar)_(n)—X—R¹—Cf  (5)

wherein V: a polymerizable group,

Ar: an aromatic ring which may have a C₁₋₁₅ alkyl group or a halogenatom,

R¹: a single bond or a C₁₋₁₅ alkylene group,

Cf: a fluoroalkyl group having at most 20 carbon atoms, which may havean etheric oxygen atom between carbon atoms,

X: —CH₂O— or —COO—

Y: a single bond, —OCH₂—, —CH₂O—, a C₁₋₄ alkylene group, —O—, —OCH₂—,—CO—, —SO₂— or —S—,

m: an integer of from 0 to 4, and

n: 0 or 1.

Advantageous Effects of Invention

As the curable composition of the present invention is sufficientlycured even without a heating step at high temperature, it can be used ina step (low temperature process) wherein the maximum heating temperatureis at most 250° C., and a cured film having an excellent solventresistance, a low dielectric constant and a favorable liquid repellencyon the surface can be obtained. In the present invention, “a favorableliquid repellency” means both favorable water repellency and favorableoil repellency.

According to the process for producing a cured film of the presentinvention, a cured film having an excellent solvent resistance, a lowdielectric constant and a favorable liquid repellency on the surface canbe formed without a heating step at high temperature. Accordingly, it isapplicable to a low temperature process using a substrate having a lowheat resistance. Further, in a case where the substrate has a largearea, warpage of the substrate can be prevented.

The cured film obtainable by curing the curable composition of thepresent invention is useful as a gate insulating film for an organicthin-film transistor.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional view schematically illustrating oneembodiment of an organic thin-film transistor using the cured film ofthe present invention.

FIG. 2 is a cross-sectional view schematically illustrating anotherembodiment of an organic thin-film transistor using the cured film ofthe present invention.

FIG. 3 is a cross-sectional view illustrating a pattern forming step ina process for producing the organic thin-film transistor shown in FIG.2.

FIG. 4 is a graph illustrating the gate voltage (VG)-drain current (ID)characteristics of the organic thin-film transistor produced in Example91 when the drain voltage (VD) is −15 V.

FIG. 5 is a graph illustrating the gate voltage (VG)-drain current (ID)characteristics of the organic thin-film transistor produced in Example92 when the drain voltage (VD) is −15 V.

FIG. 6 is a graph illustrating the gate voltage (VG)-drain current (ID)characteristics of the organic thin-film transistor produced in Example93 when the drain voltage (VD) is −15 V.

FIG. 7 is a graph illustrating the gate voltage (VG)-drain current (ID)characteristics of the organic thin-film transistor produced in Example94 when the drain voltage (VD) is −15 V.

FIG. 8 is a graph illustrating the gate voltage (VG)-drain current (ID)characteristics of the organic thin-film transistor produced in Example95 when the drain voltage (VD) is −15 V.

FIG. 9 is a graph illustrating the gate voltage (VG)-drain current (ID)characteristics of the organic thin-film transistor produced in Example96 when the drain voltage (VD) is −15 V.

DESCRIPTION OF EMBODIMENTS

In the present invention, a crosslinkable functional group is afunctional group capable of being polymerized by a radical. In thepresent invention, a radical is generated from a radical polymerizationinitiator (D) by an action of an external energy, this radical bringsabout a polymerization reaction of the crosslinkable functional group,and this polymerization reaction brings about reactions such aspolymerization, crosslinking and chain elongation of a compound havingthe crosslinkable functional group. The compound having a crosslinkablefunctional group in the present invention is the after-mentionedprepolymer (A), compound (B), copolymer (C) and the like.

In the present invention, as the external energy, heat or light isemployed. They may be used in combination.

In a case where heat is employed as the external energy, a thermalinitiator (D1) may be used in combination. The reaction temperature ofthe crosslinkable functional group is preferably at least 40° C., morepreferably at least 60° C., particularly preferably at least 70° C.,since if it is too low, stability of the compound having thecrosslinkable functional group or a composition containing it duringstorage cannot be secured. The upper limit of the reaction temperatureis at most the upper limit of the heating temperature acceptable in thestep for producing the cured film, and for example, at most the heatresistant temperature of a substrate. When the crosslinkable functionalgroup is reactive at a lower temperature, such a compound is applicableto a lower temperature process. For example, the reaction temperature ofthe crosslinkable functional group is preferably at most 250° C.,particularly preferably at most 200° C.

In a case where light (actinic rays) is employed as the external energy,the compound having the crosslinkable functional group and aphotoinitiator (D2) are used in combination. In such a case, the curablecomposition at the exposed portion is cured by irradiation with actinicrays in an exposure step. As the case requires, heating may be conductedafter the exposure and/or development step.

The crosslinkable functional group in the present invention may, forexample, be a carbon-carbon unsaturated double bond which may undergopolymerization by a radical, a carbon-carbon unsaturated triple bondwhich may undergo polymerization by a radical, a ring which will beopened by a radical, a group containing them.

The above unsaturated double bond and unsaturated triple bond may bepresent in the interior of the molecular chain (hereinafter sometimesreferred to as internal olefin type) or may be present at the terminal(hereinafter sometimes referred to as terminal olefin type), but ispreferably present at the terminal in view of a high reactivity. In thecase of the unsaturated double bond, it may be the internal olefin typeor the terminal olefin type, but is preferably the terminal olefin type.Being present in the interior of the molecular chain includes beingpresent in a part of an aliphatic ring such as a cycloolefin. Theterminal olefin type crosslinkable functional group is preferably analkenyl group having at most 4 carbon atoms or an alkynyl group havingat most 4 carbon atoms.

Specifically, it may, for example, be a vinyl group, an allyl group, anisopropenyl group, a 3-butenyl group, a methacryloyl group, amethacryloyloxy group, an acryloyl group, an acryloyloxy group, avinyloxy group, an allyloxy group, a trifluorovinyl group, atrifluorovinyloxy group, an ethynyl group, a1-oxocyclopenta-2,5-dien-3-yl group, a cyano group, an alkoxysilylgroup, a diarylhydroxymethyl group, a hydroxyfluolenyl group, acyclobutarene ring or an oxirane ring.

The crosslinkable functional group in the present invention ispreferably a crosslinkable functional group selected from the groupconsisting of a vinyl group, an allyl group, an ethynyl group, avinyloxy group, an allyloxy group, an acryloyl group, an acryloyloxygroup, a methacryloyl group and a methacryloyloxy group, in view of ahigh reactivity thereby to obtain a cured film having a high crosslinkdensity.

The crosslinkable functional group in the after-mentioned prepolymer (A)is particularly preferably a vinyl group or an ethynyl group, in view ofa low reactivity at the time of producing the prepolymer (A) and afavorable reactivity in the presence of a radical polymerizationinitiator (D).

The crosslinkable functional group in the after-mentioned compound (B)is more preferably a crosslinkable functional group selected from thegroup consisting of an acryloyl group, an acryloyloxy group, amethacryloyl group and a methacryloyloxy group in view of a highreactivity and availability, and is particularly preferably an acryloylgroup or an acryloyloxy group in view of a higher reactivity.

The crosslinkable functional group in the after-mentioned copolymer (C)is particularly preferably an acryloyl group, an acryloyloxy group, amethacryloyl group and a methacryloyloxy group in view of a highreactivity with the crosslinkable functional group of another compound.

Each of the after-mentioned prepolymer (A), compound (B) and copolymer(C) may have two or more types of crosslinkable functional groups in onemolecule. Further, the crosslinkable functional groups in the prepolymer(A), the compound (B) and the copolymer (C) which coexist in the curablecomposition may be the same or different.

In this specification, a methacryloyl group and a methacryloyloxy groupwill generically be referred to as a methacryloyl(oxy) group. The sameapplies to an acryloyl(oxy) group. Further, an acryloyl group and amethacryloyl group will generically be referred to as a (meth)acryloylgroup. The same applies to a (meth)acryloyloxy group. Further, all ofthem may sometimes be generically referred to as a (meth)acryloyol(oxy)group.

<Fluorinated Polyarylene Prepolymer (A)>

The fluorinated polyarylene prepolymer (A) (hereinafter sometimesreferred to simply as a prepolymer (A)) has a polyarylene structurewherein a plurality of aromatic rings are bonded via a single bond or alinking group, and at the same time it has fluorine atoms and acrosslinkable functional group. By the curable composition containingthe prepolymer (A), the obtainable cured film can have a low dielectricconstant.

The crosslinkable functional group of the prepolymer (A) does notsubstantially undergo a reaction at the time of producing the prepolymer(A), and by applying an external energy in the presence of the radicalpolymerization initiator (D), it undergoes a radical polymerizationreaction to cause crosslinking between molecules of the prepolymer (A)or chain elongation. Further, it is considered to react with thecrosslinkable functional groups of the compound (B) and the copolymer(C) to form a cured film together with them. As mentioned above, thecrosslinkable functional group in the prepolymer (A) is particularlypreferably a vinyl group or an ethynyl group.

The linking group in the polyarylene structure may, for example, be anether bond (—O—), a sulfide bond (—S—), a carbonyl group (—CO—) or asulfonyl group (—SO₂—). Among prepolymers (A), one having a structurewherein aromatic rings are bonded to one another by a linking groupincluding an ether bond (—O—) is referred to as a fluorinatedpolyarylene ether prepolymer. The prepolymer (A) in the presentinvention preferably contains such a fluorinated polyarylene etherprepolymer, and it is particularly preferred that the prepolymer (A)consists solely of the fluorinated polyarylene ether prepolymer.

As a specific example of such a linking group containing an ether bond,an ether bond (—O—) composed solely of an etheric oxygen atom or analkylene group containing an etheric oxygen atom in its carbon chainmay, for example, be exemplified.

Among prepolymers (A), a fluorinated polyarylene ether prepolymer isparticularly preferred in that it has an etheric oxygen atom, wherebythe molecular structure has flexibility, and the flexibility of thecured film is good.

The prepolymer (A) has fluorine atoms. As it has fluorine atoms, thedielectric constant and the dielectric loss of a cured film tend to below, such being desirable as a material to form an insulating film. Whenthe dielectric constant and dielectric loss of an insulating film arelow, it is possible to prevent delay of a signal propagation velocityand to obtain a device excellent in electrical properties.

Further, as it has fluorine atoms, the water absorption of the curedfilm becomes low, whereby it is possible to prevent a change in thebonded state at the bonded electrodes and wiring portions therearound,or it is possible to prevent modification (such as rusting) of metals.It presents a substantial effect to improve the reliability of a device.

A preferred example of such a prepolymer (A) may be a prepolymerobtainable by reacting, in the presence of a dehydrohalogenating agentsuch as potassium carbonate, a fluorinated aromatic compound such asperfluoro(1,3,5-triphenylbenzene) or perfluorobiphenyl; a phenoliccompound such as 1,3,5-trihydroxybenzene or1,1,1-tris(4-hydroxyphenyl)ethane; and a crosslinkable functionalgroup-containing aromatic compound such as pentafluorostyrene,acetoxystyrene, chloromethylstyrene or pentafluorophenylacetylene. Thereaction may be carried out by a known method.

The reaction is carried out preferably in a solvent. The solvent may,for example, be preferably a solvent containing an aprotic polar solventsuch as N,N-dimethylacetamide, N,N-dimethylformamide,N-methylpyrrolidone, dimethylsulfoxide or sulfolane. The polar solventmay contain toluene, xylene, benzene, tetrahydrofuran, benzotrifluoride,xylenehexafluoride or the like within a range where the solubility ofthe prepolymer to be formed will not be lowered, and the condensationreaction will not adversely be affected. When such a component iscontained, the polarity (dielectric constant) of the solvent is changed,and it is possible to control the reaction rate.

The number average molecular weight (Mn) of the prepolymer (A) ispreferably from 1,000 to 100,000, particularly preferably from 5,000 to50,000. When the number average molecular weight (Mn) is at least thelower limit of the above range, the flexibility of the obtainable curedfilm will not be lowered, and when it is at most the upper limit of theabove range, purification of the curable composition will be easy.

The number average molecular weight (Mn) in this specification is amolecular weight calculated as polystyrene obtained by measurement bymeans of gel permeation chromatography using an analytical curveprepared by using a standard polystyrene sample having a known molecularweight.

<Compound (B)>

The compound (B) is a compound having a number average molecular weight(Mn) of from 140 to 5,000, having at least two crosslinkable functionalgroups and having no fluorine atoms. By incorporating the compound (B)in the curable composition, a cured film having a higher hardness willbe produced.

The number average molecular weight (Mn) of the compound (B) ispreferably from 200 to 3,000, particularly preferably from 250 to 2,500.When it is at least the lower limit of the above range, evaporation byheating is less likely to occur. When it is at most the upper limit ofthe above range, the viscosity of the compound (B) can be controlled tobe low, and a uniform curable composition can easily be obtainable whenit is mixed with the prepolymer (A).

As the compound (B) has at least two crosslinkable functional groups, itcan crosslink molecules. The compound (B) preferably has from 2 to 20,particularly preferably from 2 to 8 crosslinkable functional groups.

The crosslinkable functional groups of the compound (B) contain nofluorine atoms and are preferably groups which react in the same step asthe step in which the crosslinkable functional group of the prepolymer(A) undergoes a radical polymerization reaction.

The crosslinkable functional groups of the compound (B) at least undergoa reaction with the compound (B) to cause crosslinking or chainelongation. It is considered that they react with the crosslinkablefunctional groups of the prepolymer (A) and the copolymer (C) to form acured film together with them. The crosslinkable functional groups ofthe compound (B) are preferably (meth)acryloyl(oxy) groups, morepreferably (meth)acryloyloxy groups, particularly preferably acryloylgroups or acryloyloxy groups.

Specific examples of the compound (B) may, for example, bedipentaerythritol triacrylate triundecylate, dipentaerythritolpentaacrylate monoundecylate, ethoxylated isocyanuric acid triacrylate,∈-caprolactone-modified tris-(2-acryloxyethyl)isocyanurate,9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene, polyethylene glycoldiacrylate, polyethylene glycol dimethacrylate, polypropylene glycoldiacrylate, polypropylene glycol dimethacrylate, ethoxylated bisphenol Adiacrylate, ethoxylated bisphenol A dimethacrylate, propoxylatedbisphenol A diacrylate, propoxylated bisphenol A dimethacrylate,1,10-decanediol diacrylate, 1,6-hexanediol diacrylate, 1,6-hexanedioldimethacrylate, 1,4-butanediol dimethacrylate, 1,3-butanedioldimethacrylate, hydroxypivalic acid neopentyl glycol diacrylate,1,9-nonanediol diacrylate, 1,9-nonanediol dimethacrylate, neopentylglycol diacrylate, neopentyl glycol dimethacrylate, pentaerythritoltriacrylate, trimethylolpropane triacrylate, ethoxylatedtrimethylolpropane triacrylate, propoxylated trimethylolpropanetriacrylate, triallyl cyanurate, triallyl isocyanurate, trimethallylisocyanurate, 1,4-butanediol divinyl ether, 1,9-nonanediol divinylether, cyclohexane dimethanol divinyl ether, triethylene glycol divinylether, trimethylolpropane trivinyl ether, pentaerythritol tetravinylether, 2-(2-vinyloxyethoxy)ethyl acrylate, 2-(2-vinyloxyethoxy)ethylmethacrylate, trimethylolpropane diallyl ether, pentaerythritol triallylether, dipentaerythritol hexaacrylate, pentaerythritol tetraacrylate, anethoxylated pentaerythritol tetraacrylate represented by the followingformula (1), a propoxylated pentaerythritol tetraacrylate represented bythe following formula (2), ditrimethylolpropane tetraacrylate,tricyclodecane dimethanol diacrylate, tricyclodecane dimethanolmethacrylate, and a compound represented by the following formula (3).

Further, polyester acrylates (a compound obtained by modifying bothterminals of a condensate of a dihydric alcohol and a dibasic acid withacrylic acid: tradename Aronix (M-6100, M-6200, M-6250 or M-6500),manufactured by TOAGOSEI CO., LTD.; and a compound obtained by modifyingterminal hydroxy groups of a condensate of a polyhydric alcohol and apolybasic acid, with acrylic acid: tradename Aronix (M-7100, M-7300K,M-8030, M-8060, M-8100, M-8530, M-8560 or M-9050) manufactured byTOAGOSEI CO., LTD.) may also be used. These products are available fromcommercial products.

-   -   (In the formula, l+m+n+o is from 4 to 35.)

-   -   (In the formula, l+m+n+o is about 4.)

Particularly preferred as the compound (B) to be used in the presentinvention is, in view of the availability and the reactivity,ethoxylated isocyanuric acid triacrylate, 1,10-decanediol diacrylate,1,9-nonanediol diacrylate, 1,9-nonanediol dimethacrylate,trimethylolpropane triacrylate, dipentaerythritol hexaacrylate,pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate ortricyclodecane dimethanol diacrylate.

The content of the compound (B) contained in the curable composition ispreferably from 10 to 80 parts by mass, more preferably from 15 to 70parts by mass, particularly preferably from 20 to 60 parts by mass basedon the total amount (100 parts by mass) of the prepolymer (A) and thecompound (B). When the proportion of the compound (B) is at least thelower limit of the above range, a sufficient effect of improving thecuring property when cured at low temperature will be obtained, and thesolvent resistance of the obtainable cured film will sufficiently beimproved. Further, when the content of the compound (B) is at most theupper limit of the above range, the dielectric constant of the curedfilm will sufficiently be low.

<Copolymer (C)>

The curable composition of the present invention contains a copolymer(C). When it contains the copolymer (C), the liquid repellency on thesurface of the cured film will be improved.

The copolymer (C) is a polymer having units (c1) having a fluoroalkylgroup (hereinafter sometimes referred to as a Cf group) having at most20 carbon atoms which may have an etheric oxygen atom between carbonatoms, and units (c2) having a crosslinkable functional group. The unit(c1) has no crosslinkable functional group.

The crosslinkable functional groups of the copolymer (C) are consideredto react with the crosslinkable functional groups of the prepolymer (A)and the compound (B) to form a cured film together with them. Asdescribed above, the crosslinkable functional groups of the copolymer(C) are particularly preferably (meth)acryloyl groups or(meth)acryloyloxy groups in view of high reactivity with thecrosslinkable functional groups of other compounds.

The Cf group in the unit (c1) may be linear or branched. The Cf groupmay have an etheric oxygen atom between carbon atoms. Further, thenumber of carbon atoms in the Cf group is at most 20. The number ofcarbon atoms in the Cf group includes all the carbon atoms to whichfluorine atoms or trifluoromethyl groups are bonded, and is defined sothat the total number of carbon atoms becomes smallest.

The Cf group is preferably such that the number of fluorine atoms basedon the total number of fluorine atoms and hydrogen atoms is at least80%, particularly preferably 100%.

The fluoroalkyl group may, for example, be specifically CF₃, CF₂CF₃,CF(CF₃)₂, CH(CF₃)₂, CF₂CHF₂, (CF₂)₂CF₃, (CF₂)₃CF₃, (CF₂)₄CF₃, (CF₂)₅CF₃,(CF₂)₆CF₃, (CF₂)₇CF₃, (CF₂)₈CF₃, (CF₂)₉CF₃, (CF₂)₁₁CF₃ or (CF₂)₁₅CF₃.

Further, the fluoroalkyl group having an etheric oxygen atom may, forexample, be specifically CF(CF₃)O(CF₂)₅CF₃, CF₂O(CF₂CF₂O)_(p)CF₃ (p isan integer of from 1 to 8), CF(CF₃)O(CF₂CF(CF₃)O)_(q)C₆F₁₃ (q is aninteger of from 1 to 4) or CF(CF₃)O(CF₂CF(CF₃)O)_(r)C₃F₇ (r is aninteger of from 1 to 5).

The Cf group is preferably a perfluoroalkyl group, whereby the liquidrepellency of the surface of the obtainable cured film will be morefavorable. Further, the number of carbon atoms in the Cf group ispreferably from 2 to 20, more preferably from 2 to 15, particularlypreferably from 4 to 8, whereby not only excellent liquid repellencywill be obtained but also the compatibility of the after-mentionedmonomer having the Cf group with another monomer to be copolymerizedwill be favorable.

The units (c1) having a Cf group in the copolymer (C) are preferablyformed by polymerizing a monomer having a Cf group. Otherwise, the units(c1) having a Cf group may be obtained by various modification methodsof reacting a compound having a Cf group with a polymer having areactive moiety.

The units (c1) in the copolymer (C) are preferably units formed bypolymerization of a monomer, and in such a case, a polymerizable group(a group of the same type as the crosslinkable functional group) of themonomer is lost by polymerization, and accordingly the unit (c1) has nocrosslinkable functional group.

Now, a monomer (c1 m) to give units (c1) having a Cf group will bedescribed below.

The monomer (c1m) is preferably a derivative (a derivative having apolymerizable group) of e.g. a monool having a Cf group, a monoepoxidehaving a Cf group, a monocarboxylic acid having a Cf group or amonosulfonic acid having a Cf group, particularly preferably aderivative of a monool having a Cf group.

The monool having a Cf group is preferably a monool represented byHO—R—Cf. R is a single bond or a bivalent organic group and ispreferably an alkylene group. However, the bivalent organic group is notlimited to an alkylene group and may be —R¹¹—NR²¹—CO— or —R¹¹—NR²¹—SO₂—.R¹¹ is an alkylene group, and R²¹ is a hydrogen atom or an alkyl group.Further, in the case of a monool having a hydroxy group directly bondedto a carbon atom of a fluoroalkyl group (for example, HO—CH(CF₃)₂), Rmay be a single bond.

In a case where R is an alkylene group, its number of carbon atoms ispreferably from 1 to 10, more preferably from 2 to 6, particularlypreferably from 2 to 4. The number of carbon atoms in R¹¹ is alsopreferably the same, and R²¹ is preferably a hydrogen atom or an alkylgroup having at most 4 carbon atoms.

In a case where R is a C₁₋₁₀ alkylene group, it may, for example, bespecifically —CH₂—, —CH₂CH₂—, —CH(CH₃)—, —CH₂CH₂CH₂—, —C(CH₃)₂—,—CH(CH₂CH₃)—, —CH₂CH₂CH₂CH₂—, —CH(CH₂CH₂CH₃)—, —CH₂(CH₂)₃CH₂— or—CH(CH₂CH(CH₃)₂)—. R¹ is preferably a linear alkylene group,particularly preferably —CH₂—, —CH₂CH₂—, —CH₂CH₂CH₂— or —CH₂CH₂CH₂CH₂—.

The polymerizable group is preferably a vinyl group, an allyl group, a(meth)acryloyl group, a (meth)acryloyloxy group, a vinyloxy group or anallyloxy group, particularly preferably a vinyl group or a(meth)acryloyloxy group.

The monomer (dm) is particularly preferably a compound having a residueof the monool having a Cf group and the above polymerizable group. Sucha monomer may be a compound represented by the following formula (4)(hereinafter referred to as monomer (4)):V-Q-R—Cf  (4)

wherein V: a polymerizable group,

Q: a single bond or a bivalent organic group,

Cf: a fluoroalkyl group which may have an etheric oxygen atom betweencarbon atoms, and

R: a single bond or a bivalent organic group.

In the above monomer (4), R is the residue of the above monool, and ispreferably a single bond or an alkylene group as mentioned above. Apreferred alkylene group is the same as above.

In the above monomer (4), the polymerizable group represented by V ispreferably a vinyl group, an allyl group, a (meth)acryloyl group, a(meth)acryloyloxy group, a vinyloxy group or an allyloxy group,particularly preferably a vinyl group or a (meth)acryloyloxy group.

In the above monomer (4), Q may be a single bond. In such a case, V is apolymerizable group having an oxygen atom at the terminal of theconnecting bond, and the oxygen atom is an oxygen atom in an ether bond,an oxygen atom at the alcohol residue side of an ester bond, or thelike. Such an oxygen atom is an oxygen atom derived from the monoolhaving a Cf group. In a case where Q is a single bond, V is particularlypreferably a (meth)acryloyloxy group.

In the above monomer (4), Q may also be a bivalent organic group. Insuch a case, Q is a bivalent organic group having an oxygen atom at theterminal of the bond on the R side. The oxygen atom is an oxygen atom ofan ether bond, an oxygen atom on the alcohol residue side of an esterbond, or the like. This oxygen atom is an oxygen atom derived from themonool having a Cf group. In a case where Q is a bivalent organic group,its number of carbon atoms is preferably at most 25, and is preferablyat most 12 when it has one aromatic ring as described hereinafter, atmost 18 when it has two such aromatic rings, and at most 6 when it hasno aromatic ring.

In a case where Q is a bivalent organic group, Q preferably has anaromatic ring. In such a case, the moiety on the R side is preferably—CH₂O— or —COO— bonded to the aromatic ring. The moiety on the V side isthe connecting bond of the aromatic ring or an alkylene group bonded tothe aromatic ring, and the number of carbon atoms in such an alkylenegroup is preferably at most 4, particularly preferably 1 or 2. V ispreferably a vinyl group, an allyl group, a (meth)acryloyloxy group, avinyloxy group or an allyloxy group, directly bonded to the aromaticring, or a (meth)acryloyloxy group bonded to the aromatic ring by meansof the above alkylene group. V is particularly preferably a vinyl groupor a (meth)acryloyloxy group, directly bonded to the aromatic ring, or a(meth)acryloyloxy group bonded to the aromatic ring by means of amethylene group or a dimethylene group.

In a case where Q has the aromatic ring, the aromatic ring may be amonocyclic aromatic ring, a condensed aromatic ring or a connectedpolycyclic aromatic ring. The aromatic ring may, for example, be abenzene ring, a naphthalene ring, a benzofurane ring, a benzimidazolering, a benzoxazole ring or an anthracene ring, and is preferably abenzene ring in view of the cost. Further, at least one of hydrogenatoms on the aromatic ring may be substituted by a C₁₋₁₅ alkyl group ora halogen atom. The number of carbon atoms in the alkylene group as thesubstituent is preferably at most 4, and the halogen atom is preferablya fluorine atom or a chlorine atom.

The aromatic ring in Q is preferably bivalent (i.e. has two connectingbonds), and in a case where Q has a plurality of aromatic rings, each ofthem is preferably a bivalent aromatic ring. The aromatic ring in Q ispreferably a phenylene group or a polyphenylene group having two orthree phenylene groups connected. In the case of a polyphenylene group,the plurality of phenylene groups may be directly bonded or may bebonded by means of a linking group. The linking group is preferably aC₁₋₄ alkylene group, —O—, —OCH₂—, —CO—, —SO₂—, —S— or the like,particularly preferably —OCH₂—. In a case where the aromatic ring is apolyphenylene group, it is preferred that V and R are bonded todifferent aromatic rings.

In a case where Q is a bivalent organic group having no aromatic ring, Qis preferably —R¹²—O— or —R¹²—COO— (wherein R¹² is an alkylene group ora cycloalkylene group each having at most 10 carbon atoms).

In a case where Q is an organic group having an aromatic ring, Q ispreferably a bivalent group represented by —(CH₂)_(m)—Ar—(Y—Ar)_(n)—X—.Ar is an aromatic ring which may have a C₁₋₁₅ alkylene group or ahalogen atom, X is —CH₂O— or —COO—, Y is a single bond, —OCH₂—, —CH₂O—,a C₁₋₄ alkylene group, —O—, —OCH₂—, —CO—, —SO₂— or —S—, m is an integerof from 0 to 4, and n is 0 or 1.

The above Ar is preferably a phenylene group which may have a C₁₋₄ alkylgroup or a halogen atom, particularly preferably a phenylene grouphaving no substituent. Y is preferably —OCH₂— or —CH₂O—. The monomer (4)having such Q is preferably a compound represented by the followingformula (5):V—(CH₂)_(m)—Ar—(Y—Ar)_(n)—X—R¹—Cf  (5)wherein V and Cf are the same groups as in the formula (4), and R¹ is asingle bond or a C₁₋₁₀ alkylene group.

The monomer (4) is preferably a compound represented by the formula(4-1), (4-2), (4-3), (4-4) or (4-5). The compounds represented by theformulae (4-2) to (4-5) are respectively a part of the compoundrepresented by the above formula (5):V¹—R¹—Cf¹  (4-1)V²-Ph-X—R¹—Cf¹  (4-2)V¹—(CH₂)_(k)-Ph-X—R¹—Cf¹  (4-3)V²-Ph-Y¹-Ph-X—R¹—Cf¹  (4-4)V¹—(CH₂)_(k)-Ph-Y¹-Ph-X—R¹—Cf¹  (4-5)

wherein

Cf¹: a C₂₋₁₅ perfluoroalkyl group,

V¹: a (meth)acryloyloxy group,

V²: a vinyl group or a (meth)acryloyloxy group,

R¹: a single bond or a C₁₋₁₀ alkylene group,

Ph: a phenylene group,

X: —CH₂O— or —COO—,

Y¹:—OCH₂— or —CH₂O—, and

k: 1 or 2.

In a case where the Cf group present in a side chain in the copolymer(C) is a linking group having X and is bonded to the main chain, thelinking group is likely to decompose the carbon atom of the main chainand the Cf group in the presence of light and/or ozone, so that adecomposition residue containing the Cf group is likely to leave fromthe copolymer (C). In a case where the Cf group further has the above Y¹in addition to X, the linking group is likely to undergo a decompositionreaction in the presence of light and/or ozone and as a result, thedecomposition residue containing the Cf group is more likely to leavefrom the main chain of the copolymer (C).

Therefore, by irradiating the cured film of the curable composition ofthe present invention with light or by bringing it into contact withozone, the Cf group leaves from the surface of the cured film, theliquid repellency on the surface of the cured film is decreased, and thesurface of the cured film is relatively lyophilic. By utilizing suchcharacteristics, it is possible to form a pattern of a liquid repellentportion and a lyophilic portion on the surface of the cured film e.g. byirradiating the surface of the cured film with light by means of a maskpattern.

In the case of carrying out light irradiation or ozone treatment on thesurface of the cured film as mentioned above, the cured film ispreferably a cured film formed by thermally curing the curablecomposition of the present invention. Accordingly, the copolymer (C)having units (c1) having a linking group having X is preferably used asblended with the curable composition to be thermally cured.

The monomer (c1 m) other than the above-mentioned monomer may be areaction product of a monoepoxide having a Cf group and (meth)acrylicacid, a reaction product of a monocarboxylic acid having a Cf group anda hydroxyalkyl(meth)acrylate, a reaction product of a monosulfonic acidhaving a Cf group and a hydroxyalkyl(meth)acrylate, or the like. Forexample, by reaction of a compound having a perfluoroalkyl group and aglycidyl group with (meth)acrylic acid, a compound having a hydroxyalkylgroup having a perfluoroalkyl group bonded, and a (meth)acryloyloxygroup bonded, is obtained.

The compound represented by the formula (4-1) may be CH₂═CHCOOCH₂CF₃,CH₂═CCH₃COOCH₂CF₃, CH₂═CHCOOCH₂CF₂CF₃, CH₂═CCH₃COOCH₂CF₂CF₃,CH₂═CHCOOCH(CF₃)₂, CH₂═CCH₃COOCH(CF₃)₂, CH₂═CHCOOCH₂(CF₂)₂CF₃,CH₂═CCH₃COOCH₂(CF₂)₂CF₃, CH₂═CHCOOCH₂CH₂(CF₂)₂CF₃,CH₂═CCH₃COOCH₂CH₂(CF₂)₂CF₃, CH₂═CHCOOCH₂CH₂(CF₂)₃CF₃,CH₂═CCH₃COOCH₂CH₂(CF₂)₃CF₃, CH₂═CHCOOCH₂CH₂(CF₂)₄CF₃,CH₂═CCH₃COOCH₂CH₂(CF₂)₄CF₃, CH₂═CHCOOCH₂CH₂(CF₂)₅CF₃,CH₂═CCH₃COOCH₂CH₂(CF₂)₅CF₃, CH₂═CHCOOCH₂CH₂(CF₂)₇CF₃,CH₂═CCH₃COOCH₂CH₂(CF₂)₇CF₃, CH₂═CHCOOCH₂CH₂(CF₂)₉CF₃,CH₂═CCH₃COOCH₂CH₂(CF₂)₉CF₃, CH₂═CHCOOCH₂CH₂(CF₂)₁₁CF₃,CH₂═CCH₃COOCH₂CH₂(CF₂)₁₁CF₃, CH₂═CHCOOCH₂CH₂(CF₂)₁₅CF₃,CH₂═CCH₃COOCH₂CH₂(CF₂)₁₅CF₃, CH₂═CHCOOCH₂CF(CF₃)O(CF₂)₅CF₃,CH₂═CCH₃COOCH₂CH₂CF(CF₃)O(CF₂)₅CF₃, CH₂═CHCOOCH₂CF₂O(CF₂CF₂O)_(p)CF₃ (pis from 1 to 8), CH₂═CCH₃COOCH₂CH₂CF₂O(CF₂CF₂O)_(p)CF₃ (p is from 1 to8), CH₂═CHCOOCH₂CF(CF₃)O(CF₂CF(CF₃)O)_(q)C₆F₁₃ (q is from 1 to 4),CH₂═CCH₃COOCH₂CH₂CF(CF₃)O(CF₂CF(CF₃)O)_(q)C₆F₁₃ (q is from 1 to 4),CH₂═CHCOOCH₂CF(CF₃)O(CF₂CF(CF₃)O)_(r)C₃F₇ (r is an integer of from 1 to5) or CH₂═CCH₃COOCH₂CH₂CF(CF₃)O(CF₂CF(CF₃)O)_(r)C₃F₇ (r is an integer offrom 1 to 5).

The compound represented by the formula (4-2) may, for example, be acompound represented by the following formula (4-2a), a compoundrepresented by the following formula (4-2b) or a compound represented bythe following formula (4-2c):

The compound represented by the formula (4-3) may, for example, be acompound represented by the following formula (4-3a):

The compound represented by the formula (4-5) may, for example, be acompound represented by the following formula (4-5a):

Particularly preferred as the monomer (c1m) is, in view of availability,CH₂═CHCOOCH(CF₃)₂, CH₂═CCH₃COOCH(CF₃)₂, CH₂═CHCOOCH₂CH₂(CF₂)₃CF₃,CH₂═CCH₃COOCH₂CH₂(CF₂)₃CF₃, CH₂═CHCOOCH₂CH₂(CF₂)₅CF₃ orCH₂═CCH₃COOCH₂CH₂(CF₂)₅CF₃. Further, with a view to promotingdecomposition in the presence of light and/or ozone, particularlypreferred is a compound represented by the formula (4-2a), (4-2b),(4-2c), (4-3a) or (4-5a).

The fluorine content in the copolymer (C) is preferably from 5 to 60mass %, particularly preferably from 8 to 40 mass %. When the fluorinecontent is at least the lower limit of the above range, a favorableliquid repellency on the surface of the cured film will easily beobtained, and when it is at most the upper limit of the above range, afavorable adhesion between the cured film and a layer adjacent theretowill easily be obtained.

The proportion of the units (c1) in the copolymer (C) is preferably from10 to 90 mass %, more preferably from 15 to 90 mass %, particularlypreferably from 20 to 85 mass %. When it is at least the lower limit ofthe above range, a favorable liquid repellency on the surface of thecured film will easily be obtained, and when it is at most the upperlimit of the above range, the curable composition is easily dissolved ina solvent.

The unit (c2) has a crosslinkable functional group. The unit (c2) has noCf group and has no polyarylene structure. The number of thecrosslinkable functional group in the unit (c2) is preferably 1. Thecrosslinkable functional group in the unit (c2) is particularlypreferably a (meth)acryloyol group or a (meth)acryloyloxy group. Asmentioned above, the crosslinkable functional groups of the compound (B)and the crosslinkable functional groups of the copolymer (C) may be thesame or different.

As the unit (c2) is derived from a monomer, a polymerizable group whichthe monomer has (a group of the same type as the crosslinkablefunctional group) is lost by polymerization, and usually thecrosslinkable functional group in the unit (c2) is not a functionalgroup which the monomer has. Accordingly, usually, the crosslinkablefunctional group in the unit (c2) is a crosslinkable functional groupintroduced after formation of the copolymer.

The units (c2) having a crosslinkable functional group in the copolymer(C) are preferably introduced into the copolymer (C) by variousmodification methods of reacting a compound having a crosslinkablefunctional group with a polymer having a reactive moiety. Suchmodification methods may properly be selected from known methods.Specifically, a monomer having a reactive functional group (hereinafterreferred to as monomer (c4m)) is copolymerized to produce a copolymerhaving reactive functional groups, and a compound (hereinafter referredto as compound (c2c)) having a second reactive functional group whichreacts with and is bonded to the reactive functional group of theobtained copolymer, and a crosslinkable functional group, is reacted toproduce the copolymer (C). The unit (c2) is a unit formed by bonding ofthe unit (c4) formed by polymerization of the monomer (c4m) and thecompound (c2c).

As a specific modification method, the following methods may, forexample, be mentioned. (i) A method of reacting an acid anhydride havinga crosslinkable functional group with a copolymer obtained bycopolymerizing a monomer having a hydroxy group, (ii) a method ofreacting a compound having an isocyanate group and a crosslinkablefunctional group with a copolymer obtained by copolymerizing a monomerhaving a hydroxy group, (iii) a method of reacting a compound having anacyl chloride group and a crosslinkable functional group with acopolymer obtained by copolymerizing a monomer having a hydroxy group,(iv) a method of reacting a compound having a hydroxy group and acrosslinkable functional group with a copolymer obtained bycopolymerizing an acid anhydride having a polymerizable group, (v) amethod of reacting a compound having an epoxy group and a crosslinkablefunctional group with a copolymer obtained by copolymerizing a monomerhaving a carboxy group, or (vi) a method of reacting a compound having acarboxy group and a crosslinkable functional group with a copolymerobtained by copolymerizing a monomer having an epoxy group.

In a case where the compound (c2c) is reacted with the copolymer havingthe units (c4), the compound (c2c) may be reacted with substantially allthe reactive functional groups in the copolymer or may be reacted with apart of the reactive functional groups in the copolymer. In the lattercase, the obtainable copolymer (C) has units (c4) formed bypolymerization of the monomer (c4m). The copolymer (C) to be used forthe curable composition may have such units (c4). Further, in a casewhere the reactive functional group of the unit (c4) may adverselyaffect the curable composition, the reactive functional group may beconverted to an inert group by reacting a compound having a secondfunctional group which reacts with and is bonded to the reactivefunctional group of the copolymer and having no crosslinkable functionalgroup, with the reactive functional group of the unit (c4).

The unit (c4) remaining in the copolymer (C) and a unit having theabove-mentioned inert group derived therefrom, are considered as theafter-mentioned units (c3).

The monomer having a hydroxy group in the above (i), (ii) and (iii) andthe compound having a hydroxy group and a crosslinkable functional groupin (iv) may, for example, be 2-hydroxyethyl(meth)acrylate or4-hydroxybutyl(meth)acrylate.

The acid anhydride having a crosslinkable functional group in the above(i) and the acid anhydride having a polymerizable group in (iv) may, forexample, be specifically maleic anhydride, itaconic anhydride,citraconic anhydride or phthalic anhydride.

The compound having an isocyanate group and a crosslinkable functionalgroup in the above (ii) may, for example, be specifically2-(meth)acryloyloxyethyl isocyanate or 1,1-bis(acryloyloxymethyl)ethylisocyanate.

The compound having an acyl chloride group and a crosslinkablefunctional group in the above (iii) may, for example, be specifically(meth)acryloyl chloride or 3-butenoyl chloride.

The monomer having a carboxy group in the above (v) and the compoundhaving a carboxy group and a crosslinkable functional group in (vi) may,for example, be specifically (meth)acrylic acid.

The compound having an epoxy group and a crosslinkable functional groupin the above (v) and the monomer having an epoxy group in (vi) may, forexample, be glycidyl(meth)acrylate or 3,4-epoxycyclohexylmethylacrylate.

Preferred as the unit (c2) is a unit formed by reacting a compoundhaving an isocyanate group and a crosslinkable functional group with acopolymer obtained by copolymerizing a monomer having a hydroxy group,or a unit formed by reacting a compound having an acyl chloride groupand a crosslinkable functional group with a copolymer obtained bycopolymerizing a monomer having a hydroxy group. Particularly preferredis, in view of favorable reactivity with the prepolymer (A), a unitformed by reacting a compound selected from the group consisting of(meth)acryloyl chloride, 2-methacryloyloxyethyl isocyanate and2-acryloyloxyethyl isocyanate, with a copolymer obtained bycopolymerizing at least one monomer selected from the group consistingof 2-hydroxyethyl(meth)acrylate and 4-hydroxybutyl(meth)acrylate, as amonomer having a hydroxy group.

In a case where the copolymer (C) comprises the units (c1) and the units(c2), as a preferred proportion of the units (c2) in the copolymer (C),the content of the units (c1) is such an amount that the fluorinecontent in the copolymer (C) is within the above preferred range, andthe rest is the units (c2).

In a case where the copolymer (C) comprises the units (c1), the units(c2) and units (c3), it is preferred that the content of the units (c1)is such an amount that the fluorine content in the copolymer (C) iswithin the above preferred range, the content of the units (c3) iswithin the after-mentioned preferred range, and the rest is the units(c2).

The proportion of the units (c2) in the copolymer (C) is preferably from10 to 90 mass %, more preferably from 10 to 85 mass %, particularlypreferably from 15 to 80 mass %. When it is at least the lower limit ofthe above range, a favorable reactivity with the prepolymer (A) and thecompound (B) will be obtained, and when it is at most the upper limit ofthe above range, a favorable liquid repellency on the surface of thecured film will easily be obtained.

The copolymer (C) may have units (c3) other than the units (c1) having aCf group and the units (c2) having a crosslinkable functional group asthe case requires within a range not to impair the effect of improvingthe liquid repellency. As mentioned above, when the copolymer (C) hasthe units (c4) or units derived from the units (c4) having nocrosslinkable functional group, such units are units (c3).

The units (c3) are preferably introduced into the copolymer (C) bypolymerizing the monomer (c3m). They are also preferably introduced tothe polymer by various modification methods of reacting an appropriatecompound with the copolymer (C) having a reactive moiety. Now, themonomer (c3m) to give units (c3) will be described with reference toexamples.

The monomer (c3m) to give the unit (c3) may be the above monomer (c4m),or a hydrocarbon type olefin, a vinyl ether, an isopropenyl ether, anallyl ether, a vinyl ester, an allyl ester, a (meth)acrylate, a(meth)acrylamide, an aromatic vinyl compound, a chloroolefin or aconjugated diene. Such compounds may have a functional group, and such afunctional group may, for example, be a hydroxy group, a carbonyl groupor an alkoxy group. They may be used alone or in combination of two ormore.

The monomer (c3m) to give the unit (c3) may, for example, bespecifically acrylic acid, methacrylic acid, methyl(meth)acrylate,ethyl(meth)acrylate, n-propyl(meth)acrylate, isopropyl(meth)acrylate,n-butyl(meth)acrylate, isobutyl(meth)acrylate, sec-butyl(meth)acrylate,t-butyl(meth)acrylate, n-pentyl(meth)acrylate,3-methylbutyl(meth)acrylate, n-hexyl(meth)acrylate,2-ethyl-n-hexyl(meth)acrylate, n-octyl(meth)acrylate,cyclohexyl(meth)acrylate, isobornyl(meth)acrylate,(1,1-dimethyl-3-oxobutyl)(meth)acrylate,2-acetoacetoxyethyl(meth)acrylate, 2-methoxyethyl(meth)acrylate,2-ethoxyethyl(meth)acrylate, (meth)acrylamide, N-vinylacetamide,N-vinylformamide, N-(1,1-dimethyl-3-oxobutyl)(meth)acrylamide,N-methoxymethyl(meth)acrylamide orN,N-bis(methoxymethyl)(meth)acrylamide. In view of availability,preferred is acrylic acid, methacrylic acid, cyclohexyl(meth)acrylate orisobornyl(meth)acrylate.

The proportion of the units (c3) in the copolymer (C) is preferably atmost 70 mass %, more preferably at most 50 mass %, particularlypreferably at most 20 mass %. The lower limit is preferably 0%. When theproportion of the units (c3) is within the above range, sufficientcontents of the units (c1) and the units (c2) will be secured, and theliquid repellency on the surface of the cured film and the curingproperty of the curable composition will not be impaired.

Preferred combinations of the units in the copolymer (C) are as follows.In the following, (—CH₂—C—) represents a moiety of two carbon atomsconstituting the main chain.

(Combination 1)

unit (c1): (—CH₂—C—)CH₃COOCH₂CH₂(CF₂)₅CF₃

unit (c2): (—CH₂—C—)CH₃COOCH₂CH₂OCONHCH₂CH₂OCOCH═CH₂

unit (c3): (—CH₂—C—)CH₃COOH

(Combination 2)

unit (c1): (—CH₂—C—)CH₃COOCH(CF₃)₂

unit (c2): (—CH₂—C—)CH₃COOCH₂CH₂OCONHCH₂CH₂OCOCH═CH₂

(Combination 3)

unit (c1): (—CH₂—C—)CH₃COOCH₂CH₂(CF₂)₃CF₃

unit (c2): (—CH₂—C—)CH₃COOCH₂CH₂OCONHCH₂CH₂OCOCH═CH₂

(Combination 4)

unit (c1): (—CH₂—C—)CH₃COOCH₂CH₂(CF₂)₅CF₃

unit (c2): (—CH₂—C—)CH₃COOCH₂CH₂OCONHCH₂CH₂OCOCH═CH₂

(Combination 5)

unit (c1): unit derived from a compound represented by the formula(4-2b)

unit (c2): (—CH₂—C—)CH₃COOCH₂CH₂OCONHCH₂CH₂OCOCH═CH₂

(Combination 6)

unit (c1): unit derived from a compound represented by the formula(4-2a)

unit (c2): (—CH₂—C—)CH₃COOCH₂CH₂OCONHCH₂CH₂OCOCH═CH₂

The preferred weight ratio of the units in the copolymer (C) ispreferably such that the units (c1):the units (c2):the units (c3)=10 to90:10 to 90:0 to 70, more preferably 15 to 90:10 to 85:0 to 50,particularly preferably 20 to 90:10 to 80:0 to 20. The charge weightratio of the monomer which gives the units (c1), the monomer and thereactive compound which give the units (c2), and the monomer which givesthe units (c3), at the time of polymerization, is also the same.

Preparation of the copolymer (C) is preferably carried out in a solvent.The solvent may, for example, be an alcohol such as ethanol, 1-propanol,2-propanol, 1-butanol or ethylene glycol; a ketone such as acetone,methyl isobutyl ketone or cyclohexanone; a cellosolve such as2-methoxyethanol, 2-ethoxyethanol or 2-butoxyethanol; a carbitol such as2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)ethanol or2-(2-butoxyethoxy)ethanol; an ester such as methyl acetate, ethylacetate, n-butyl acetate, ethyl lactate, n-butyl lactate, ethyleneglycol monomethyl ether acetate, propylene glycol monomethyl etheracetate, ethylene glycol diacetate or glycerin triacetate; or an ethersuch as diethylene glycol dimethyl ether or diethylene glycol methylethyl ether. They may be used alone or in combination of two or more.

Further, a polymerization initiator is preferably used. Thepolymerization initiator may, for example, be a known organic peroxide,inorganic peroxide or azo compound. The organic peroxide or theinorganic peroxide may be used as a redox catalyst in combination with areducing agent. Such polymerization initiators may be used alone or incombination of two or more.

The organic peroxide may, for example, be benzoyl peroxide, lauroylperoxide, isobutyryl peroxide, t-butyl hydroperoxide or t-butyl-α-cumylperoxide.

The inorganic peroxide may, for example, be ammonium persulfate, sodiumpersulfate, potassium persulfate, hydrogen peroxide or a percarbonate.

The azo compound may, for example, be 2,2′-azobisisobutylonitrile,1,1-azobis(cyclohexane-1-carbonitrile),2,2′-azobis(2,4-dimethylvaleronitrile),2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile), dimethyl2,2′-azobisisobutyrate or 2,2′-azobis(2-amidinopropane)dihydrochloride.

As the case requires, a chain transfer agent such as a mercaptan or ahalogenated alkyl is preferably used.

The mercaptan may, for example, be n-butyl mercaptan, n-dodecylmercaptan, t-butyl mercaptan, ethyl thioglycolate, 2-ethylhexylthioglycolate or 2-mercaptoethanol. The halogenated alkyl may, forexample, be chloroform, carbon tetrachloride or carbon tetrabromide.They may be used alone or in combination of two or more.

As the case requires, a known polymerization inhibitor is preferablyblended. The polymerization inhibitor may, for example, be2,6-di-t-butyl-p-cresol.

In a case where the obtained copolymer is modified also, the samesolvent as above may be used. However, a solvent which may react withthe compound (c2c) cannot be used. Preparation of the copolymer iscarried out in a solvent, then the compound (c2c) is added and reactedto obtain the copolymer (C).

Further, modification may be carried out in the presence of a catalystor a neutralizing agent. For example, in a case where a compound havingan isocyanate group and a crosslinkable functional group is reacted witha copolymer having hydroxy groups, a tin compound or the like may beused as the catalyst. The tin compound may, for example, be dibutyltindilaurate, dibutyltin di(maleic monoester), dioctyltin dilaurate,dioctyltin di(maleic monoester) or dibutyltin diacetate. They may beused alone or in combination of two or more.

In a case where a compound having an acyl chloride group and acrosslinkable functional group is reacted with a copolymer havinghydroxy groups, a basic catalyst may be used. The basic catalyst may,for example, be triethylamine, pyridine, dimethyl aniline ortetramethylurea. They may be used alone or in combination of two ormore.

The number average molecular weight (Mn) of the copolymer (C) ispreferably from 1,000 to 50,000, particularly preferably from 3,000 to20,000. When the number average molecular weight is at least the lowerlimit of the above range, the copolymer (C) will sufficiently migrate tothe surface of a coating film, whereby a liquid repellency will beobtained. When it is at most the upper limit of the above range, thecompatibility with the prepolymer (A) in the curable composition will befavorable, and a coating film free from defects will be formed.

The content of the copolymer (C) contained in the curable composition ispreferably from 0.1 to 20 parts by mass, particularly preferably from0.2 to 15 parts by mass based on the total amount (100 parts by mass) ofthe prepolymer (A) and the compound (B). When the content of thecopolymer (C) is at least the lower limit of the above range, asufficient effect of improving the liquid repellency will easily beobtained. When it is at most the upper limit of the above range, anobtainable film will have favorable physical properties.

<Application of Copolymer (C)>

Among the copolymers (C), a copolymer (hereinafter referred to as acopolymer (C-5)) having units (hereinafter referred to as units (c1-5))having a monomer represented by the above formula (5) polymerized andthe units (c2) and optionally the units (c3) is a copolymer useful foranother application due to its specific characteristics. That is, byhaving a linking group containing —CH₂O— or —COO— bonded to the aromaticring, the Cf group present in the side chain of the copolymer ischaracterized in that it easily leaves from the copolymer. Accordingly,by light irradiation and/or ozone treatment on the surface of a curedproduct of a curable composition containing such a copolymer, the liquidrepellency on the surface of the cured film is lowered, and the surfaceof the cured product is relatively lyophilic. Accordingly, the copolymerhaving the units (c1-5) and the units (c2) and optionally the units (c3)is not limited for the curable composition of the present invention andis useful as a liquid repellency-imparting agent to be blended in aradical-curable composition (a curable composition containing at leastone compound having a curable functional group as a curable component).As described hereinafter, for example, the surface of a thermally curedproduct of a curable composition containing the liquidrepellency-imparting agent is irradiated with light by means of a maskpattern, whereby the portion irradiated with light is converted to alyophilic surface, thereby to obtain a surface having a pattern of aliquid-repellent portion and a lyophilic portion.

The surface of a cured product of a curable composition containing thecopolymer (C-5) repels water and oil, and even if water, oil or the likeis attached, such an attached matter will easily be removed from thesurface. The attached matter is not limited to a liquid and may be asolid having an adherent surface. Accordingly, the copolymer (C-5) has,as a component in a curable composition, a property to impartcharacteristics to reduce the adhesion or characteristics to makeremoval of the attached matter easy, to the surface of the cured productof the curable composition. For example, when an oily substance such assebum is attached (particularly when fingerprints are attached) to thesurface of the cured product, the attached matter can easily be removed.In a case where such characteristics are to be utilized also, asmentioned above, a surface having such characteristics partially loweredmay be formed as mentioned above.

In the present invention, including the above liquidrepellency-imparting agent, an agent which imparts characteristics toimpart non-adhesion of a liquid or a solid to the surface will bereferred to as a non-adhesion imparting agent.

In the curable composition containing the copolymer (C-5), the curablecomponent other than the copolymer (C-5) is preferably the compound (B)or a compound having a crosslinkable functional group equivalent thereto(for example, a compound having one crosslinkable functional group). Thecrosslinkable functional group of such compounds is preferably a(meth)acryloyl(oxy) group, more preferably a (meth)acryloyloxy group,particularly preferably an acryloyl group or an acryloyloxy group.

<Radical Polymerization Initiator (D)>

The curable composition of the present invention may be thermallycurable or photocurable. In a case where it is thermally curable, athermal initiator (D1) is incorporated in the curable composition as aradical polymerization initiator (D), and in a case where it isphotocurable, a photoinitiator (D2) is incorporated.

The photocurable composition may be used as a negative photosensitivematerial.

<Photoinitiator (D1)>

The thermal initiator (D1) may be known one. It may, for example, beazobisisobutylonitrile, benzoyl peroxide, tert-butyl hydroperoxide,cumene hydroperoxide, di-tert-butyl peroxide or dicumyl peroxide. Theymay be used alone or in combination of two or more.

In view of the decomposition temperature, azobisisobutylonitrile orbenzoyl peroxide is preferred.

The content of the thermal initiator (D1) in the curable composition ispreferably from 1 to 20 parts by mass, particularly preferably from 5 to15 parts by mass based on the total amount (100 parts by mass) of theprepolymer (A) and the compound (B). When it is at least the lower limitof the above range, a sufficient effect of improving the curing propertywhen cured at low temperature will be obtained, and the solventresistance of the cured film will sufficiently be improved. When it isat most the upper limit of the above range, the storage stability of thecurable composition will be favorable.

<Photoinitiator (D2)>

The photoinitiator (D2) may be known one for a photocurable composition.It may, for example, be specifically an oxime ester derivative such as1,2-octanedione, 1-[4-(phenylthio)-, 2-(o-benzoyloxime)] (for example,tradename: IRGACURE OXE01), or ethanone1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl], 1-(o-acetyloxime) (forexample, tradename: IRGACURE OXE02); an α-aminoalkylphenone compoundsuch as IRGACURE 369 (tradename) or IRGACURE 907 (tradename); or anacylphosphine oxide compound such as DAROCUR TPO (tradename) (eachmanufactured by Ciba Specialty Chemicals).

In view of the reactivity of a radical generated, preferred is IRGACUREOXE01 or IRGACURE OXE02.

The content of the photoinitiator (D2) in the curable composition ispreferably from 1 to 20 parts by mass, particularly preferably from 3 to15 parts by mass, based on the total amount (100 parts by mass) of theprepolymer (A) and the compound (B). When it is at least the lower limitof the above range, a sufficient effect of improving the curing propertywhen cured at low temperature will be obtained, and the solventresistance of the cured film will sufficiently be improved. When it isat most the upper limit of the above range, the storage stability of thecurable composition will be favorable.

<Additives>

To the curable composition, an additive selected from various additiveswell known in the coating field, for example, stabilizers such as anultraviolet absorber, an antioxidant and a thermal polymerizationinhibitor; surfactants such as a leveling agent, a defoaming agent, aprecipitation-preventing agent and a dispersant; plasticizers; andthickeners, may be incorporated, as the case requires, within a rangenot to impair the effects of the present invention.

Further, in a case where the cured film is a material remaining as afunctional component in a final product without being removed during theproduction process (hereinafter referred to as a component material),for example, like an interlayer insulating film, an adhesion-improvingagent such as a silane coupling agent may be incorporated to the curablecomposition. It is preferred to incorporate an adhesion-improving agentto the curable composition, since the adhesion between the cured film ofthe curable composition and a layer adjacent thereto will be improved.Otherwise, the adhesion can be improved also by a method ofpreliminarily applying an adhesion-improving agent to the adjacentlayer.

The content of the additive in the curable composition is preferablyfrom 0.0001 to 30 parts by mass, more preferably from 0.0001 to 20 partsby mass, particularly preferably from 0.0001 to 10 parts by mass basedon the total amount (100 parts by mass) of the prepolymer (A) and thecompound (B).

<Solvent>

As the curable composition of the present invention contains thecompound (B) which is usually liquid, the compound (B) functions as asolvent, and the curable composition can be formed into a coatingcomposition which can be applied. Further, the lower the viscosity ofthe compound (B), or the larger the amount of the compound (B) blended,the lower the viscosity of the curable composition of the presentinvention. However, it is difficult to make the composition have aviscosity so low that sufficient application is possible only by thecurable composition of the present invention in many cases. Accordingly,usually, it is preferred to add a solvent to the curable composition ofthe present invention to form a coating composition.

The coating composition is applied on a substrate, and the solvent isremoved, whereby a film of the curable composition of the presentinvention is formed. Usually, removal of the solvent is carried out byevaporating the solvent from the film of the coating composition.Accordingly, the solvent is required to have a boiling point lower thanthose of the components of the curable composition of the presentinvention. Among the components of the curable composition of thepresent invention, the compound having the lowest boiling point isusually the compound (B), and accordingly as the solvent, a solventhaving a boiling point lower than that of the compound (B) in thecurable composition is used. On the other hand, as the compound (B) inthe curable composition of the present invention, it is preferred to usea compound having a boiling point sufficiently higher than those ofsolvents commonly used.

The solvent may be known one. It may, for example, be specificallypropylene glycol monomethyl ether acetate (hereinafter referred to asPGMEA), mesitylene, N,N-dimethylacetamide, cyclohexanone ortetrahydrofuran.

The content of the solvent in the coating composition is preferably from100 to 5,000 parts by mass, particularly preferably from 100 to 3,000parts by mass based on the total amount (100 parts by mass) of theprepolymer (A) and the compound (B).

<Curable Composition>

As the curable composition and the coating composition of the presentinvention, the following combinations are preferred.

(Combination 1)

Curable Composition 1

A curable composition comprising:

Prepolymer (A): a prepolymer comprising perfluorobiphenyl,1,3,5-trihydroxybenzene and acetoxystyrene in an amount of from 40 to 90parts by mass based on the total amount (100 parts by mass) of theprepolymer (A) and the compound (B),

Compound (B): at least one member selected from the group consisting ofethoxylated isocyanuric acid triacrylate, 1,10-decanediol diacrylate,1,9-nonanediol diacrylate, 1,9-nonanediol dimethacrylate,trimethylolpropane triacrylate, dipentaerythritol hexaacrylate,pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate andtricyclodecane dimethanol diacrylate in an amount of from 10 to 60 partsby mass based on the total amount (100 parts by mass) of the prepolymer(A) and the compound (B),

Copolymer (C): a copolymer obtained by reacting a copolymer obtained bycopolymerizing, as a monomer having a Cf group which gives the units(c1), a (meth)acrylate of an alkanol (number of carbon atoms: 2 to 4excluding a perfluoroalkyl group) having a perfluoroalkyl group (numberof carbon atoms: 2 to 10), or a compound represented by the formula(4-2a), (4-2b), (4-2c), (4-3a) or (4-5a); as the monomer (c4m), at leastone member selected from the group consisting of2-hydroxyethyl(meth)acrylate and 4-hydroxybutyl(meth)acrylate; and asthe monomer (c3m), (meth)acrylic acid, with at least one member selectedfrom the group consisting of (meth)acryloyl chloride,2-methacryloyloxyethyl isocyanate and 2-acryloyloxyethyl isocyanate asthe compound (c2c) in an amount of from 0.1 to 20 parts by mass based onthe total amount (100 parts by mass) of the prepolymer (A) and thecompound (B), and

Photoinitiator (D1): at least one member selected from the groupconsisting of benzoyl peroxide and 2,2′-azobisisobutylonitrile in anamount of from 3 to 10 parts by mass based on the total amount (100parts by mass) of the prepolymer (A) and the compound (B).

Coating Composition 1

A coating composition comprising the curable composition 1 and a solvent(at least one member selected from the group consisting of PGMEA andcyclohexanone) in an amount of from 100 to 3,000 parts by mass based onthe total amount (100 parts by mass) of the prepolymer (A) and thecompound (B).

(Combination 2)

Curable Composition 2

A curable composition comprising:

Prepolymer (A): a prepolymer comprising perfluorobiphenyl,1,3,5-trihydroxybenzene and acetoxystyrene in an amount of from 40 to 90parts by mass based on the total amount (100 parts by mass) of theprepolymer (A) and the compound (B),

Compound (B): at least one member selected from the group consisting ofethoxylated isocyanuric acid triacrylate, 1,10-decanediol diacrylate,1,9-nonanediol diacrylate, 1,9-nonanediol dimethacrylate,trimethylolpropane triacrylate, dipentaerythritol hexaacrylate,pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate andtricyclodecane dimethanol diacrylate in an amount of from 10 to 60 partsby mass based on the total amount (100 parts by mass) of the prepolymer(A) and the compound (B),

Copolymer (C): a copolymer obtained by reacting a copolymer obtained bycopolymerizing, as a monomer having a fluoroalkyl group (Cf) which givesthe units (c1), a (meth)acrylate of an alkanol (number of carbon atoms:2 to 4 excluding a perfluoroalkyl group) having a perfluoroalkyl group(number of carbon atoms: 2 to 10); as the monomer (c4m), at least onemember selected from the group consisting of2-hydroxyethyl(meth)acrylate and 4-hydroxybutyl(meth)acrylate; and asthe monomer (c3m), (meth)acrylic acid, with at least one member selectedfrom the group consisting of (meth)acryloyl chloride,2-methacryloyloxyethyl isocyanate and 2-acryloyloxyethyl isocyanate asthe compound (c2c) in an amount of from 0.1 to 20 parts by mass based onthe total amount (100 parts by mass) of the prepolymer (A) and thecompound (B), and

Photoinitiator (D2): at least one member selected from the groupconsisting of IRGACURE OXE01 and IRGACURE OXE02 in an amount of from 5to 20 parts by mass based on the total amount (100 parts by mass) of theprepolymer (A) and the compound (B).

Coating Composition 2

A coating composition comprising the curable composition 2 and a solvent(at least one member selected from the group consisting of PGMEA andcyclohexanone) in an amount of from 100 to 3,000 parts by mass based onthe total amount (100 parts by mass) of the prepolymer (A) and thecompound (B) blended.

<Process for Producing Cured Film>

The process for producing a cured film of the present invention is aprocess for forming a film of the curable composition on a substrate,followed by curing. Here, “forming a film of the curable composition ona substrate” includes both a case where a film of the curablecomposition is directly formed on a substrate and a case where anoptional layer is formed on a substrate, and a film of the curablecomposition is formed thereon. Further, in a case where a coatingcomposition is used, it includes a case where a film of the coatingcomposition is formed on a substrate, and then the solvent is removed toform a film of the curable composition. That is, a film of the coatingcomposition is formed on a substrate, and the coating composition iscured by means of at least one heating step. Further, a film obtained bycuring the film of the curable composition will be referred to as acured film. It is preferred to use a coating composition with a view toobtaining a cured film having a uniform thickness.

The thickness of the cured film is not particularly limited and mayoptionally be selected. For example, the thickness is preferably at alevel of from 0.1 to 100 μm, particularly preferably from 0.2 to 50 μm.

Forming of a film of the curable composition directly on a substrate orforming of a film of the coating composition on a substrate may becarried out by a known coating method such as a spin coating method, adip coating method, a spray coating method, a die coating method, a barcoating method, a doctor coating method, an extrusion coating method, ascanning coating method, a brush coating method, a potting method, aninkjet method or printing. In view of uniform thickness, preferred is aspin coating method or a scan coating method.

In a case where curing is carried out by thermal curing, a film of thecurable composition is formed on a substrate, followed by a heating step(curing step) to form a cured film. Before the curing step, a heatingstep (prebaking) may be carried out.

In a case where curing is carried out by photo-curing, a film of thecurable composition is formed on a substrate, followed by a heating step(prebaking) as the case requires, the film is irradiated with light(exposed) and then as the case requires, a heating step (curing step) iscarried out to obtain a cured film. In view of the cost, preferred is amethod of forming a film of the curable composition on a substrate,followed by irradiation with light (exposure) to obtain a cured film.Preferred is a method of forming a film of the coating composition on asubstrate, and removing the solvent by a heating step (prebaking) toform a film of the curable composition, followed by irradiation withlight (exposure) to obtain a cured film. At the time of exposure, aphotomask may be used.

The light to be applied is not particularly limited so long as it islight having a wavelength to which the photoinitiator (D2) contained inthe curable composition is sensitive. Usually, light to be used forcuring is ultraviolet light, but is not limited thereto.

In the case of carrying out microfabrication by means ofphotolithography, by selective irradiation with light (exposure), theirradiated portion (exposed portion) is cured. Accordingly, by carryingout development (a step to remove the non-exposed portion by beingdissolved or dispersed in a solvent) after exposure to remove thenon-exposed portion, and removing the solvent remaining in the curedportion, a microfabricated cured film is obtained. As the case requires,a heating step (curing step) may be carried out after development. Insuch a case, the remaining solvent can be removed in this heating step(curing step). Further, after exposure and before development, a heatingstep (post-exposure baking) may be carried out as the case requires.

In the present invention, production of the cured film can be carriedout at a low temperature with a heating temperature in the heating stepof at most 250° C. In such a case, when at least two heating steps arecarried out, for example, prebaking and/or post-exposure baking and thecuring step are carried out, the heating temperature in all the heatingsteps is at most 250° C. In a case where the substrate has a heatresistant temperature lower than 250° C., the heating temperature in theheating step is at most the heat resistant temperature of the substrate.

In the present invention, the heating temperature being at most 250° C.means that the temperature of an object to be heated will not exceed250° C. Specifically, the temperature of a heating apparatus such as ahot plate or an oven is set to be at most 250° C.

In the process for producing a cured film of the present invention,prebaking is carried out for the purpose of removing the solvent when acoating composition is used, and is carried out at a relatively lowheating temperature. The heating temperature in prebaking is notparticularly limited and is preferably from 40 to 100° C. for example.

The curing step and the post-exposure baking are carried out for thepurpose of curing the film, and are carried out at a relatively highheating temperature. The heating temperature in the curing step and thepost-exposure baking is preferably at least 80° C., particularlypreferably at least 100° C. If the temperature is lower than such arange, effects by the curing step or the post-exposure baking tend to beinsufficient. Further, as shown in the after-mentioned Examples, withthe curable composition of the present invention, a cured film withfavorable solvent resistance can be obtained even when the heatingtemperature in the curing step and the post-exposure baking is from 100to 150° C. The lower the heating temperature, the less the substratewill be damaged, such being favorable.

Accordingly, the heating step in the process for producing a cured filmof the present invention is carried out preferably at a heatingtemperature of at most 200° C. In a case where at least two heatingsteps are carried out, the heating temperature in all the heating stepsis at most 200° C. In a case where the substrate has a heat resistanttemperature lower than 200° C., the heating temperature in the heatingstep is at most the heat resistant temperature of the substrate.Specifically, the temperature of a heating apparatus such as a hot plateor an oven is set to be at most 200° C.

The cured film in the present invention is preferably produced by usingthe coating composition at a temperature of at most 250° C. in all theheating steps included in the procedure to obtain the cured film.Further, even in the case of photo-curing, a step which requires heatingto remove the solvent or for other purposes is required, and in such aheating step also, the heating temperature is preferably at most 250° C.Accordingly, the process for producing a cured film is preferably aprocess for producing a cured film, which comprises forming a film ofthe coating composition on a substrate, and thermally curing orphoto-curing the curable composition by a step containing at least oneheating step to produce the cured film, wherein the heating temperaturein all the heating steps is at most 250° C.

The substrate to be used in the present invention may, for example, be aplastic, glass or silicon. For example, a plastic such as polycarbonate,polyethylene terephthalate, polyethylene naphthalate, polyethersulfoneor polyimide is preferably used, whereby excellent mechanicalflexibility will be obtained.

The application of the cured film obtainable by curing the curablecomposition of the present invention is preferably a functional film.The functional film is a film having a function such as electricalinsulation, chemical or physical protection or non-adhesion on itssurface, in semiconductor devices or other various electronic devices.Specifically, it may, for example, be an interlayer insulating film forflexible devices, a protective film for flexible devices, a gateinsulating film for organic thin-film transistors, a gate insulatingfilm for oxide thin-film transistors, a capacitor insulating film, agate insulating film for memory transistors, passivation forsemiconductors, a protective film for semiconductor devices, aninterlayer insulating film for multilayer interconnection for highdensity mounting, an insulating layer for organic electroluminescentelements, an insulating film for rewiring, cover coating for copper-cladplates, a solder resist film, a liquid crystal alignment film, aprotective film for color filters, a resin post for e.g. semiconductordevices, and partition walls for e.g. color filters.

The curable composition of the present invention, which comprises theprepolymer (A), the compound (B) and the radical polymerizationinitiator (D), can sufficiently be cured by heating at 250° C. or lower,preferably at 200° C. or lower. That is, as shown in the after-mentionedExamples and Comparative Examples, if the curable composition containsthe prepolymer (A) and contains neither of the compound (B) and theradical polymerization initiator (D), by thermal curing (curingtemperature: 150° C.), although a cured film is formed, the cured filmwill easily be dissolved in a solvent. Further, by photo-curing, nocured film will be formed, and the coating film will easily be dissolvedin the development step.

Further, if the curable composition contains no compound (B) even thoughit contains the prepolymer (A) and the radical polymerization initiator(D), by thermal curing, although a cured film is formed, it will beswollen and its film thickness increases if it is immersed in a solvent,and the reduction in film thickness is significant after it is dried. Inthe case of photo-curing, the cured film will be swollen in a solventand its film thickness increases, and its film thickness will return tothe original thickness after it is dried.

Further, if the curable composition contains no radical polymerizationinitiator (D) even though it contains the prepolymer (A) and thecompound (B), in the case of thermal curing, although a cured film isformed, the cured film will easily be dissolved in a solvent. Further,in the case of photo-curing, no cured film will be formed, and thecoating film will easily be dissolved in the development step.

Whereas, when the curable composition contains the prepolymer (A), thecompound (B) and the radical polymerization initiator (D), a lowdielectric constant cured film having excellent solvent resistance willbe obtained even by thermal curing or photo-curing under the sameconditions as above.

The compound (B) is disclosed as a component to improve flatness of thefilm surface in the above Patent Document 4. However, it is a surprisingfinding that a combined use of the compound (B) and the radicalpolymerization initiator (D) in combination with the prepolymer (A), thecuring property when the curable composition is cured at low temperatureis improved, and the solvent resistance of the cured film is improved.

The reason why the curable composition can sufficiently be cured at lowtemperature by combination of the prepolymer (A), the compound (B) andthe radical polymerization initiator (D) is not clearly understood, butis estimated that by the compound (B) which functions as a reactivediluent, the glass transition temperature of the coating film beforecuring will be lowered, and the reaction of radicals becomes possibleeven at low temperature, whereby curing proceeds.

Further, by the curable composition containing the copolymer (C) inaddition to the prepolymer (A), the compound (B) and the radicalpolymerization initiator (D), an effect such that it can sufficiently becured even without a heating step at high temperature and an effect suchthat the liquid repellency on the surface of the cured film can beimproved without impairing an effect that a low dielectric constantcured film having excellent solvent resistance can be obtained. Thereason why a favorable liquid repellency can be obtained is consideredthat the fluoroalkyl group (Cf) in the copolymer (C) contributes to animprovement in the liquid repellency and that the crosslinkablefunctional group undergoes a curing reaction to contribute to thestability and the lasting effect of the liquid repellency.

With respect to a film of the curable composition of the presentinvention using a copolymer having, as the units (c1) of the copolymer(C), units having a linking group having the above X such as the units(c1-5) (i.e. the above copolymer (C-5)), the surface of the cured filmcan be converted to be lyophilic by light irradiation or ozone treatmenton the surface. Hereinafter this treatment to convert the surface of thecured film to be lyophilic will be referred to as lyophilic treatment,and a step for the lyophilic treatment will be referred to as alyophilic step. The lyophilic treatment is preferably a treatment ofapplying light. Accordingly, the present invention further provides amethod for treating a cured film, which comprises irradiating the curedfilm with light to lower the liquid repellency at the light irradiatedportion.

The lyophilic treatment is preferably a treatment of irradiating thecured film formed by thermal curing with light. This exposure may becarried out under the same conditions as the conditions for photo-curingthe curable composition of the present invention. For example, thesurface of the cured film is irradiated with light such as ultravioletlight by means of a photomask to form a cured film having a pattern of aliquid repellent portion and a lyophilic portion formed on its surface.

When the lyophilic portion of the cured film formed by the lyophilicstep is treated with a treating liquid in the following step, thetreating liquid will adhere to the lyophilic portion and will not adhereto the liquid repellent portion. Accordingly, when an electricconductor-forming liquid or an electrode-forming liquid is used as thetreating liquid for example, an electric conductor or an electrode canbe formed only on the lyophilic portion. Thus, an electric conductorpattern or an electrode pattern can easily be formed on the cured film.

Here, the surface of a cured film formed by curing the curablecomposition of the present invention containing the above copolymer(C-5) as the copolymer (C) by light irradiation has a low liquidrepellency as compared with the surface of the thermally cured film, byleaving of the Cf groups. However, even a cured film having a surfacewith a low liquid repellency can be used for applications except for anapplication for which a particularly high liquid repellent surface isrequired.

Process for Producing Semiconductor Device First Embodiment Formation ofCured Film

The cured film of the curable composition of the present invention isuseful for production of a semiconductor device.

That is, a film of a coating composition containing the curablecomposition of the present invention is formed on a substrate, and thenthe curable composition is thermally cured or photo-cured by a stepcontaining at least one heating step to produce a cured film, and asemiconductor device can suitably be produced by this process. The firstheating step after the film of the coating composition is formed isusually a step for removing the solvent.

FIG. 1 is a view illustrating an example of the first embodiment of theprocess for producing an organic thin-film transistor by using a curedfilm obtainable by curing the curable composition of the presentinvention as a gate insulating film, and is a drawing schematicallyillustrating the cross-section of the device structure.

An organic thin-film transistor of this example comprises a substrate 1,and a gate electrode 2, a gate insulating film 3 and an organicsemiconductor layer 4 formed in this order on the substrate 1, and asource electrode 5 and a drain electrode 6 further formed thereon.

The device structure of the organic thin-film transistor is various, andis not particularly limited so long as it has a gate insulating filmobtainable by curing the curable composition of the present invention.

In FIG. 1, the reference symbol 1 represents a substrate. Its preferredmaterial is the same as the material preferred as the above-describedsubstrate.

The gate electrode 2, the source electrode 5 and the drain electrode 6are formed by an electric conductor. The electric conductor to be usedfor such electrodes is not particularly limited and may, for example, bepreferably silicon, doped silicon, platinum, gold, silver, copper,chromium, aluminum, calcium, barium, indium tin oxide, indium zincoxide, zinc oxide, carbon black, a fullerene, carbon nanotubes,polythiophene, polyethylenedioxythiophene, polystyrenesulfonic acid,polyaniline, polypyrrole or polyfluorene. These electrode materials maybe used alone or in combination of two or more. Further, the materialsof the gate electrode 2, the source electrode 5 and the drain electrode6 may be the same or different.

The method for forming the electrode is not particularly limited and forexample, sputtering, vacuum deposition, spin coating, spray coating,printing or ink jet may be applicable.

As the material of the organic semiconductor layer 4, a low molecularcompound, an oligomer or a polymer may be used, and the material is notparticularly limited. The low molecular compound may, for example, bepentacene, rubrene, phthalocyanine, perylene, fullerene or a derivativethereof.

The oligomer may, for example, be oligothiophene or a derivativethereof.

The polymer may, for example, be poly-p-phenylenevinylene (PPV),polyfluorene, a fluorene-benzothiazole copolymer, afluorene-triphenylamine copolymer, a fluorene-dithiophene copolymer,polythiophene, polyaniline, polyacetylene, polypyrrole or a derivativethereof.

The organic semiconductor layer 4 may be formed by forming a layercomprising a precursor of an organic semiconductor, and then applyinglight or heat to convert the precursor to an organic semiconductor. Sucha convertible precursor material may, for example, besilylethyne-substituted pentacene or a tetrabicycloporphyrin derivative.Such a material, which can be converted to pentacene or atetrabicycloporphyrin derivative by heating, is useful as a precursormaterial for the organic semiconductor layer.

The thickness of the organic semiconductor layer 4 is not particularlylimited but is preferably from 5 nm to 100 μm, more preferably from 10nm to 10 μm, particularly preferably from 10 nm to 1 μm.

The gate insulating film 3 may be formed by the above-described <Processfor producing cured film> by using the coating composition containingthe curable composition of the present invention. The thickness of thegate insulating film 3 comprising a cured film formed by curing by heator light is not particularly limited, but the thickness t at a portionwhere no gate electrode 2 is present is preferably from 1 nm to 10 μm,more preferably from 2 nm to 5 μm, particularly preferably from 5 nm to1 μm. If the thickness of the gate insulating film 3 is to thin, aleakage current is likely to occur between the gate electrode 6 and thesource electrode 5, and if it is too thick, the driving voltage tends toincrease.

With respect to an organic thin-film transistor thus obtained, theleakage current is reduced by forming the gate insulating film 3 byusing the curable composition of the present invention. As it ispossible to make the gate insulating film 3 thin, downsizing of thedevice can be realized, and further, the driving voltage of thetransistor can be reduced.

For example, the coating composition in the after-mentioned Example 1was applied to a low resistant silicon substrate by spin coating at 700revolutions per minute for 30 seconds, heated on a hot plate at 150° C.for 2 minutes and then heated in an oven at 150° C. for 10 minutes toobtain a cured film having a thickness of 1.5 μm. The leakage current ofthe cured film was measured, whereupon the leakage current at 1.0[MV/cm] was 2.9×10⁻¹⁰ [A/cm²].

Further, with respect to the organic thin-film transistor in thisExample, as the surface of the gate insulating film 3 has a favorableliquid repellency, such effects will be obtained that molecules in theorganic semiconductor layer 4 provided on the gate insulating film 3 arelikely to be aligned, polar groups to be top sites of a carrier are lesslikely to be present on the surface, moisture and the like in the airare less likely to be adsorbed. Accordingly, the electron mobility inthe organic thin-film transistor will be high, and the stability and thereliability will improve.

Second Embodiment Lyophilic Treatment on Cured Film

With respect to the cured film of the curable composition of the presentinvention having the above specific copolymer (C-5) blended, as shown inthe after-mentioned experimental examples, the liquid repellency can belowered by irradiating the surface of the cured film with ultravioletlight or laser light. This can be suitably utilized for the process forproducing a semiconductor device.

That is, a semiconductor device can suitably be formed by a processwhich comprises forming a cured film of the curable composition of thepresent invention on a substrate, and irradiating the cured film withultraviolet light. The cured film can be formed by the method disclosedin the above first embodiment. However, the cured film is preferably acured film formed by thermal curing.

FIG. 2 is a view illustrating an example of the second embodiment of theprocess for producing an organic thin-film transistor, and is a viewschematically illustrating the cross-section of the device structure.The same constituent as in FIG. 1 is provided with the same symbol andits description is omitted.

The organic thin-film transistor in this example is significantlydifferent from the example in FIG. 1 in that a source electrode 15 and adrain electrode 16 are formed on a gate insulating film 13.

In a case where the layer under the electrodes is a cured film of thespecific curable composition of the present invention (a curablecomposition containing the above copolymer (C-5) as the copolymer (C))as in this example, formation of a finer electrode is possible bycarrying out patterning of selectively irradiating the surface of thelayer under the electrodes with ultraviolet light or laser light tochange the liquid repellency on a predetermined region.

FIG. 3 is a view schematically illustrating the patterning step. Thatis, the cured film (gate insulating film 13) of the specific curablecomposition of the present invention is irradiated with ultravioletlight or laser light by means of a photomask, whereby at the outermostlayer portion of the exposed portion, at least part of the Cf groups onthe surface of the cured film leave and are removed from the surface ofthe cured film, and the portion is converted to a lyophilic region 13 a.In FIG. 3, the reference symbol 13 b represents a non-exposed portionand a liquid repellent region. In FIG. 3, the reference symbol 13 crepresents an internal region other than the outermost layer of thecured film (gate insulating film 13).

In the cured film (gate insulating film 13), it is estimated that thelyophilic region 13 a and the liquid repellent region 13 b are notclearly distinguished from the internal region 13 c under such surfacelayers having surface properties, but the concentration of the Cf groupsis continuously changed along the thickness direction.

In the patterning step, to draw the pattern, ultraviolet light or laserlight may be employed. For example, an infrared laser, an ultravioletlamp or electron irradiation of e.g. y rays is possible. The lightsource may, for example, be a mercury lamp, a metal halide lamp, a xenonlamp, a chemical lamp or a carbon-arc lamp. The radiation may, forexample, be electron beam, X-ray or ion beam. As the laser, gas lasersuch as carbon dioxide laser, nitrogen laser, Ar laser, He/Ne laser,He/Cd laser or Kr laser, liquid laser, solid-state laser such as Nd/YAGlaser, semiconductor laser, excimer laser or the like may be used.

Then, an electric conductor or a solution 10 containing an electricconductor, as the material of the source electrode 15 and the drainelectrode 16 is applied, whereby the droplets are diffused in andapplied to only the surface of the lyophilic region 13 a, but they arenot applied to the water-repellent region 13 b which is the non-exposedportion. As a method of forming the source electrode 15 and the drainelectrode 16, ink jet, a dispenser or printing may, for example, beused.

The gate insulating film 13 and the organic semiconductor layer 14 maybe formed in the same manner as the gate insulating film 3 and theorganic semiconductor layer 4 in the example shown in FIG. 1.

The organic thin-film transistor obtainable in this example also has thesame effects as the organic thin-film transistor according to theabove-described first embodiment (FIG. 1).

EXAMPLES

Now, the present invention will be described in further detail withreference to Examples. However, it should be understood that the presentinvention is by no means restricted to such specific Examples. Theevaluation methods are as follows.

[Contact Angle]

The contact angle on the surface of a cured film was measured by using acontact angle meter CA-A (tradename) manufactured by Kyowa InterfaceScience Co., LTD. at 25° C. by means of a sessile drop method. Toevaluate the water repellency, about 1 μL of water was dropped on thecured film to measure the contact angle, and to evaluate the oilrepellency, about 1 μL of propylene glycol monomethyl ether acetate(PGMEA) was dropped to measure the contact angle.

[Relative Dielectric Constant]

The relative dielectric constant was measured by a mercury prober(manufactured by SSM, tradename: SSM-495) by carrying out CV measurementto determine the relative dielectric constant at 1 MHz.

[Solvent Resistance]

The thickness of a cured film was measured (thickness: t₀), and then thecured film was immersed in PGMEA at room temperature (from 20 to 25° C.)for one hour. Then, by using a spin coater, spin drying was carried outat 1,000 revolutions per minute for 30 seconds to measure the thickness(thickness: t₁). Then, the cured film was dried on a hot plate at 100°C. for 5 minutes and the thickness was measured (thickness: t₂). Theswell ratio and the film remaining ratio were determined from thefollowing formulae.Swell ratio(%)=(t ₁ −t ₂)/t ₀×100Film remaining ratio(%)=t ₂ /t ₀×100

The solvent resistance of the cured film was evaluated based on thestandards such that one which satisfies both a swell ratio of at most 5%and a film remaining ratio of at least 80%: “a cured film sufficientlycured, having favorable solvent resistance (represented by ◯ inTables)”, one which satisfy either one of them: “a cured filminsufficiently cured, having poor solvent resistance (represented by Δin Tables)” and one which satisfies neither of them, or one which wasnot cured: “curing failure (represented by x in Tables)”.

<Preparation of Fluorinated Polyarylene Prepolymer (A)>

Abbreviations represent the following compounds.

DMAc: N,N-dimethylacetamide

PFB: perfluorobiphenyl

Preparation Example 1 Preparation of Fluorinated Polyarylene EtherPrepolymer (A1)

In DMAc (6,620 g) solvent, PFB (450 g), pentafluorophenylacetylene (155g) and 1,3,5-trihydroxybenzene (130 g) were reacted in the presence ofpowdery molecular sieves 4 A (600 g) and sodium carbonate (600 g) at 60°C. for 45 hours to prepare prepolymer (A1). The obtained DMAc solutionof prepolymer (A1) was poured into an aqueous hydrochloric acid solution(3.5 mass % aqueous solution) for purification by reprecipitation,followed by vacuum drying to obtain 620 g of powdery prepolymer (A1).The number average molecular weight (Mn) of prepolymer (A1) was 10,000.

Preparation Example 2 Preparation of Fluorinated Polyarylene EtherPrepolymer (A2)

In DMAc (492 g) solvent, pentafluorostyrene (22 g) and1,1,1-tris(4-hydroxyphenyl)ethane (33 g) were reacted in the presence ofsodium carbonate (51 g) at 60° C. for 24 hours, and then a solutionhaving PFB (40 g) dissolved in DMAc (360 g) was added, followed byreaction at 60° C. further for 17 hours to prepare prepolymer (A2). Theobtained DMAc solution of prepolymer (A2) was poured into an aqueoushydrochloric acid solution (3.5 mass % aqueous solution) forpurification by reprecipitation, followed by vacuum drying to obtain 750g of powdery prepolymer (A2). The number average molecular weight (Mn)of prepolymer (A2) was 10,000.

Preparation Example 3 Preparation of Fluorinated Polyarylene EtherPrepolymer (A3)

In DMAc (6.2 kg) solvent, PFB (650 g) and 1,3,5-trihydroxybenzene (120g) were reacted in the presence of potassium carbonate (570 g) at 40° C.for 6 hours, and then 4-acetoxystyrene (200 g) was reacted in thepresence of a 48 mass % potassium hydroxide aqueous solution (530 g) toprepare prepolymer (A3). The obtained DMAc solution of prepolymer (A3)was poured into an aqueous hydrochloric acid solution (3.5 mass %aqueous solution) for purification by reprecipitation, followed byvacuum drying to obtain 800 g of powdery prepolymer (A3). The numberaverage molecular weight (Mn) of prepolymer (A3) was 10,000.

<Preparation of Copolymer (C)>

Abbreviations represent the following compounds.

[Monomer Having Fluoroalkyl Group (Cf)]

C6FMA: CH₂═C(CH₃)COOCH₂CH₂(CF₂)₆F

C4FMA: CH₂═C(CH₃)COOCH₂CH₂(CF₂)₄F

C8FA: CH₂═CHCOOCH₂CH₂(CF₂)₄F

iC3FMA: CH₂═C(CH₃)COOCH(CF₃)₂

Compound (4-2a): compound represented by the formula (4-2a)

Compound (4-2b): compound represented by the formula (4-2b)

Compound (4-2c): compound represented by the formula (4-2c)

Compound (4-3a): compound represented by the formula (4-3a)

Compound (4-5a): compound represented by the formula (4-5a)

[Monomer Having Carboxy Group]

MAA: methacrylic acid

[Monomer Having Hydroxy Group]

HEMA: 2-hydroxyethyl methacrylate

HBA: 4-hydroxybutyl acrylate

[Compound Having Isocyanate Group and Crosslinkable Group]

MOI: 2-methacryloyloxyethyl isocyanate

AOI: 2-acryloyloxyethyl isocyanate

[Compound Having Acyl Chloride Group and Crosslinkable Group]

AC: acryloyl chloride

[Chain Transfer Agent]

DSH: n-dodecylmercaptan

[Polymerization Initiator]

V-70: 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile) (manufactured byWako Pure Chemical Industries, Ltd.), tradename: V-70)

[Catalyst]

DBTDL: dibutyltin dilaurate

TEA: triethylamine

[Polymerization Inhibitor]

BHT: 2,6-di-t-butyl-p-cresol

Preparation Example 4 Preparation of Copolymer (C1)

In acetone (555 g) solvent, C6FMA (96 g), MAA (72 g) and HEMA (72 g)were reacted in the presence of a chain transfer agent DSH (9.7 g) and apolymerization initiator V-70 (5 g) at 40° C. for 18 hours to obtain asolution of polymer 1. The obtained acetone solution of polymer 1 waspoured into water for purification by reprecipitation, followed byvacuum drying to obtain 230 g of powdery polymer 1.

Then, in acetone (100 g) solvent, polymer 1 (100 g), MOI (36 g), DBTDL(0.2 g) and BHT (1.8 g) were reacted at 30° C. for 18 hours to preparecopolymer (C1). The obtained acetone solution of copolymer (C1) waspoured into water for purification by reprecipitation, followed byvacuum drying to obtain 135 g of powdery copolymer (C1). Of copolymer(C1), the fluorine content was 22 mass % and the number averagemolecular weight (Mn) was 7,000.

Preparation Example 5 Preparation of Copolymer (C2)

In acetone (100 g) solvent, polymer 1 (100 g) obtained in PreparationExample 4, AOI (33 g), DBTDL (0.2 g) and BHT (1.8 g) were reacted at 30°C. for 18 hours to prepare copolymer (C2). The obtained acetone solutionof copolymer (C2) was poured into water for purification byreprecipitation, followed by vacuum drying to obtain 130 g of powderycopolymer (C2). Of copolymer (C2), the fluorine content was 22 mass %and the number average molecular weight (Mn) was 7,000.

Preparation Example 6 Preparation of Copolymer (C3)

In acetone (555 g) solvent, C4FMA (96 g), MAA (72 g) and HEMA (72 g)were reacted in the presence of a chain transfer agent DSH (9.7 g) and apolymerization initiator V-70 (5 g) at 40° C. for 18 hours to obtain asolution of polymer 2. The obtained acetone solution of polymer 2 waspoured into water for purification by reprecipitation, followed byvacuum drying to obtain 230 g of powdery polymer 2.

Then, in acetone (100 g) solvent, polymer 2 (100 g), MOI (36 g), DBTDL(0.2 g) and BHT (1.8 g) were reacted at 30° C. for 18 hours to preparecopolymer (C3). The obtained acetone solution of copolymer (C3) waspoured into water for purification by reprecipitation, followed byvacuum drying to obtain 132 g of powdery copolymer (C3). Of copolymer(C3), the fluorine content was 19 mass % and the number averagemolecular weight (Mn) was 7,000.

Preparation Example 7 Preparation of Copolymer (C4)

In acetone (555 g) solvent, C8FMA (96 g), MAA (72 g) and HEMA (72 g)were reacted in the presence of a chain transfer agent DSH (9.7 g) and apolymerization initiator V-70 (5 g) at 40° C. for 18 hours to obtain asolution of polymer 3. The obtained acetone solution of polymer 3 waspoured into water for purification by reprecipitation, followed byvacuum drying to obtain 230 g of powdery polymer 3.

Then, in acetone (100 g) solvent, polymer 3 (100 g), MOI (36 g), DBTDL(0.2 g) and BHT (1.8 g) were reacted at 30° C. for 18 hours to preparecopolymer (C4). The obtained acetone solution of copolymer (C4) waspoured into water for purification by reprecipitation, followed byvacuum drying to obtain 134 g of powdery copolymer (C4). Of copolymer(C4), the fluorine content was 24 mass % and the number averagemolecular weight (Mn) was 7,000.

Preparation Example 8 Preparation of Copolymer (C5)

In acetone (555 g) solvent, C6FMA (120 g) and HEMA (120 g) were reactedin the presence of a chain transfer agent DSH (16 g) and apolymerization initiator V-70 (3.6 g) at 40° C. for 18 hours to obtain asolution of polymer 4. The obtained acetone solution of polymer 4 waspoured into water for purification by reprecipitation, followed byvacuum drying to obtain 230 g of powdery polymer 4.

Then, in acetone (100 g) solvent, polymer 4 (100 g), MOI (60 g), DBTDL(0.4 g) and BHT (3.0 g) were reacted at 30° C. for 18 hours to preparecopolymer (C5). The obtained acetone solution of copolymer (C5) waspoured into water for purification by reprecipitation, followed byvacuum drying to obtain 155 g of powdery copolymer (C5). Of copolymer(C5), the fluorine content was 23 mass % and the number averagemolecular weight (Mn) was 4,500.

Preparation Example 9 Preparation of Copolymer (C6)

In acetone (100 g) solvent, polymer 4 (100 g) obtained in PreparationExample 8, AOI (54 g), DBTDL (0.3 g) and BHT (2.7 g) were reacted at 30°C. for 18 hours to prepare copolymer (C6). The obtained acetone solutionof copolymer (C6) was poured into water for purification byreprecipitation, followed by vacuum drying to obtain 149 g of powderycopolymer (C6). Of copolymer (C6), the fluorine content was 24 mass %and the number average molecular weight (Mn) was 4,500.

Preparation Example 10 Preparation of Copolymer (C7)

In acetone (555 g) solvent, C6FMA (96 g), MAA (72 g) and HBA (72 g) werereacted in the presence of a chain transfer agent DSH (9.7 g) and apolymerization initiator V-70 (5 g) at 40° C. for 18 hours to obtain asolution of polymer 5. The obtained acetone solution of polymer 5 waspoured into water for purification by reprecipitation, followed byvacuum drying to obtain 230 g of powdery polymer 5.

Then, in acetone (100 g) solvent, polymer 5 (100 g), AC (20 g) and TEA(22 g) were reacted at 0° C. for 6 hours to prepare copolymer (C7). Theobtained acetone solution of copolymer (C7) was poured into water forpurification by reprecipitation, followed by vacuum drying to obtain 110g of powdery copolymer (C7). Of copolymer (C7), the fluorine content was27 mass % and the number average molecular weight (Mn) was 6,000.

Preparation Example 11 Preparation of Copolymer (C8)

In acetone (555 g) solvent, C6FMA (120 g) and HBA (120 g) were reactedin the presence of a chain transfer agent DSH (16 g) and apolymerization initiator V-70 (3.6 g) at 40° C. for 18 hours to obtain asolution of polymer 6. The obtained acetone solution of polymer 6 waspoured into water for purification by reprecipitation, followed byvacuum drying to obtain 230 g of powdery polymer 6.

Then, in acetone (100 g) solvent, polymer 6 (100 g), AC (31 g) and TEA(40 g) were reacted at 0° C. for 6 hours to prepare copolymer (C8). Theobtained acetone solution of copolymer (C8) was poured into water forpurification by reprecipitation, followed by vacuum drying to obtain 125g of powdery copolymer (C8). Of copolymer (C8), the fluorine content was31 mass % and the number average molecular weight (Mn) was 4,000.

Preparation Example 12 Preparation of Copolymer (C9)

In 2-butanone (245 g) solvent, iC3FMA (50 g) and HEMA (55 g) werereacted in the presence of a chain transfer agent DSH (9.1 g) and apolymerization initiator V-70 (1.2 g) at 50° C. for 24 hours, and thenreacted at 70° C. for 2 hours.

After the mixture was cooled to room temperature (20 to 25° C.), AOI (60g), DBTDL (0.2 g) and BHT (3.0 g) were charged, followed by a reactionat 40° C. for 24 hours to prepare copolymer (C9). The obtained2-butanone solution of copolymer (C9) was poured into hexane forpurification by reprecipitation, followed by vacuum drying to obtain 155g of powdery copolymer (C9). Of copolymer (C9), the fluorine content was12 mass % and the number average molecular weight (Mn) was 6,000.

Preparation Example 13 Preparation of Copolymer (C10)

In 2-butanone (199 g) solvent, the compound (4-2c) (50 g) and HEMA (35g) were reacted in the presence of a chain transfer agent DSH (5.2 g)and a polymerization initiator V-70 (0.7 g) at 50° C. for 24 hours, andthen reacted at 70° C. for 2 hours.

After the mixture was cooled to room temperature (20 to 25° C.), AOI (38g), DBTDL (0.2 g) and BHT (1.9 g) were charged, followed by a reactionat 40° C. for 24 hours to prepare copolymer (C10). The obtained2-butanone solution of copolymer (C10) was poured into hexane forpurification by reprecipitation, followed by vacuum drying to obtain 115g of powdery copolymer (C10). Of copolymer (C10), the fluorine contentwas 18 mass % and the number average molecular weight (Mn) was 5,500.

Preparation Example 14 Preparation of copolymer (C11)

In 2-butanone (197 g) solvent, the compound (4-3a) (50 g) and HEMA (34g) were reacted in the presence of a chain transfer agent DSH (5.1 g)and a polymerization initiator V-70 (0.7 g) at 50° C. for 24 hours, andthen reacted at 70° C. for 2 hours.

After the mixture was cooled to room temperature (20 to 25° C.), AOI (37g), DBTDL (0.1 g) and BHT (1.9 g) were charged, followed by a reactionat 40° C. for 24 hours to prepare copolymer (C11). The obtained2-butanone solution of copolymer (C11) was poured into hexane forpurification by reprecipitation, followed by vacuum drying to obtain 115g of powdery copolymer (C11). Of copolymer (C11), the fluorine contentwas 18 mass % and the number average molecular weight (Mn) was 6,000.

Preparation Example 15 Preparation of copolymer (C12)

In 2-butanone (184 g) solvent, the compound (4-5a) (50 g) and HEMA (29g) were reacted in the presence of a chain transfer agent DSH (4.3 g)and a polymerization initiator V-70 (0.6 g) at 50° C. for 24 hours, andthen reacted at 70° C. for 2 hours.

After the mixture was cooled to room temperature (20 to 25° C.), AOI (31g), DBTDL (0.1 g) and BHT (1.6 g) were charged, followed by a reactionat 40° C. for 24 hours to prepare copolymer (C12). The obtained2-butanone solution of copolymer (C12) was poured into hexane forpurification by reprecipitation, followed by vacuum drying to obtain 100g of powdery copolymer (C12). Of copolymer (C12), the fluorine contentwas 17 mass % and the number average molecular weight (Mn) was 6,000.

Preparation Example 16 Preparation of Copolymer (C13)

In 2-butanone (212 g) solvent, the compound (4-2a) (50 g) and HEMA (41g) were reacted in the presence of a chain transfer agent DSH (6.0 g)and a polymerization initiator V-70 (0.8 g) at 50° C. for 24 hours, andthen reacted at 70° C. for 2 hours.

After the mixture was cooled to room temperature (20 to 25° C.), AOI (44g), DBTDL (0.2 g) and BHT (2.2 g) were charged, followed by a reactionat 40° C. for 24 hours to prepare copolymer (C13). The obtained2-butanone solution of copolymer (C13) was poured into hexane forpurification by reprecipitation, followed by vacuum drying to obtain 125g of powdery copolymer (C13). Of copolymer (C13), the fluorine contentwas 19 mass % and the number average molecular weight (Mn) was 5,500.

Preparation Example 17 Preparation of Copolymer (C14)

In 2-butanone (288 g) solvent, the compound (4-2b) (50 g) and HEMA (73g) were reacted in the presence of a chain transfer agent DSH (11 g) anda polymerization initiator V-70 (1.5 g) at 50° C. for 24 hours, and thenreacted at 70° C. for 2 hours.

After the mixture was cooled to room temperature (20 to 25° C.), AOI (79g), DBTDL (0.3 g) and BHT (4.0 g) were charged, followed by a reactionat 40° C. for 24 hours to prepare copolymer (C14). The obtained2-butanone solution of copolymer (C14) was poured into hexane forpurification by reprecipitation, followed by vacuum drying to obtain 195g of powdery copolymer (C14). Of copolymer (C14), the fluorine contentwas 9 mass % and the number average molecular weight (Mn) was 5,000.

Preparation Example 18 Preparation of Copolymer (C15)

In 2-butanone (174 g) solvent, the compound (4-2b) (50 g) and HEMA (24g) were reacted in the presence of a chain transfer agent DSH (5.4 g)and a polymerization initiator V-70 (0.7 g) at 50° C. for 24 hours, andthen reacted at 70° C. for 2 hours.

After the mixture was cooled to room temperature (20 to 25° C.), AOI (27g), DBTDL (0.1 g) and BHT (1.3 g) were charged, followed by a reactionat 40° C. for 24 hours to prepare copolymer (C15). The obtained2-butanone solution of copolymer (C15) was poured into hexane forpurification by reprecipitation, followed by vacuum drying to obtain 90g of powdery copolymer (C15). Of copolymer (C15), the fluorine contentwas 18 mass % and the number average molecular weight (Mn) was 5,000.

Preparation Example 19 Preparation of Copolymer (C16)

In 2-butanone (136 g) solvent, the compound (4-2b) (50 g) and HEMA (8.1g) were reacted in the presence of a chain transfer agent DSH (3.6 g)and a polymerization initiator V-70 (0.5 g) at 50° C. for 24 hours, andthen reacted at 70° C. for 2 hours.

After the mixture was cooled to room temperature (20 to 25° C.), AOI(8.8 g), DBTDL (0.04 g) and BHT (0.4 g) were charged, followed by areaction at 40° C. for 24 hours to prepare copolymer (C16). The obtained2-butanone solution of copolymer (C16) was poured into hexane forpurification by reprecipitation, followed by vacuum drying to obtain 60g of powdery copolymer (C16). Of copolymer (C16), the fluorine contentwas 27 mass % and the number average molecular weight (Mn) was 6,500.

Example 1 to 24, 31 to 50 and 51 to 60

Using prepolymers (A) and copolymers (C) obtained in the abovePreparation Examples and the following materials, curable compositionswere prepared in blend ratios as identified in Tables 1 to 3. Using eachof the curable compositions, a cured film was formed by the followingmethod and evaluated. The evaluation results are shown in Tables.

Examples 1 to 5, 11 to 24 and 51 to 59 are Examples of thermal curing,and Examples 6 to 10, 31 to 50 and 60 are Examples of photo-curing.Examples 3 to 5, 8 to 10, 18 to 24 and 42 to 50 are ComparativeExamples, and Examples 2 and 7 are Reference Examples. The other areExamples of the present invention.

<Compound (B)>

ADCP: tricyclodecane dimethanol diacrylate (number average molecularweight (Mn): 304)

ATMPT: trimethylolpropane triacrylate (number average molecular weight(Mn): 296)

M408: ditrimethylolpropane tetraacrylate (number average molecularweight (Mn): 466)

ADPH: dipentaerythritol hexaacrylate (number average molecular weight(Mn): 578)<

Photoinitiator (D1)>

AIBN: azobisisobutylonitrile

BPO: benzoyl peroxide

<Photoinitiator (D2)>

OXE01: 1,2-octanedione,1-[4-(phenylthio)-,2-(o-benzoyloxime)]

OXE02:ethanone,1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-,1-(o-acetyloxime)

<Solvent>

PGMEA: propylene glycol monomethyl ether acetate

Examples 1 to 5, 11 to 24 and 51 to 59 Thermal Curing

The prepolymer (A), the compound (B), the copolymer (C), the thermalinitiator (D1) and the solvent were mixed in ratios as identified inTables 1, 2 and 4 to obtain coating compositions.

Each of the obtained coating compositions was applied on a glasssubstrate by spin coating at 1,000 revolutions per minute for 30seconds, and heated on a hot plate (prebaked) under heating conditionsof 150° C. for 2 minutes, and then heated in an oven at 150° C. for 10minutes (curing step) to obtain a cured film having a thickness of 1 μm.The solvent resistance of the obtained cured film was evaluated.Further, in Examples 11 to 24, the contact angle and the dielectricconstant were measured. The results are shown in Tables 1, 2 and 4.

Examples 6 to 10, 31 to 50 and 60 Photo-Curing

The prepolymer (A), the compound (B), the copolymer (C), thephotoinitiator (D2) and the solvent were mixed in ratios as identifiedin Tables 1, 3 and 4 to obtain coating compositions.

Each of the obtained coating compositions was applied on a glasssubstrate by spin coating at 1,000 revolutions per minute for 30seconds, and heated on a hot plate (prebaked) under heating conditionsof 60° C. for 90 seconds. Then, exposure with an irradiation energy of200 mJ/cm² was carried out. Exposure was carried out by using anultraviolet exposure apparatus MA-6 (tradename, manufactured by SUSSMicroTec AG.) using a high pressure mercury lamp as a light source. Withrespect to the non-exposed portion, an area of ⅓ of the substrate wasshielded from light using a metal foil or a mask.

Then, heating was carried out on a hot plate at 120° C. for 2 hours(post-exposure baking). Then, using PGMEA, paddle development wascarried out for 20 seconds, followed by spin drying at 2,000 revolutionsper minute for 30 seconds. Then, heating was carried out on a hot plateat 100° C. for 5 minutes (curing step) to obtain a cured film having athickness of 1 μm. The solvent resistance of the obtained cured film wasevaluated. Further, in Examples 31 to 50 and 60, the contact angle andthe dielectric constant were measured. The results are shown in Tables1, 3 and 4.

TABLE 1 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8 Ex. 9 Ex. 10Composition (A) A3 60 60 100 100 60 60 60 100 100 100 (parts by (B)ATMPT 40 mass) M408 40 ADPH 40 40 40 40 (C) C6 0.5 0.5 (D1) BPO 6 6 8(D2) OXE01 10 10 10 Solvent PGMEA 250 250 250 250 250 250 250 250 250250 Evaluation Swell ratio (%) 1 3 — 10 — 1 5 X 10 X Film remainingratio (%) 99 95 0 80 0 100 100 100 Solvent resistance ◯ ◯ X Δ X ◯ ◯ — Δ—

TABLE 2 Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. 11 12 1314 15 16 17 18 19 20 21 22 23 24 Composition (A) A1 80 80 80 100 100(parts by A2 80 80 100 100 mass) A3 60 60 100 100 100 (B) ADCP 20 ATMPT20 20 M408 40 40 ADPH 20 20 (C) C1 10 C2 5 0.5 10 5 C3 10 1 C4 10 5 C5 1C6 0.5 C7 10 C8 1 5 (D1) AIBN 8 8 10 10 10 10 10 BPO 8 6 8 6 6 10 8Solvent PGMEA 250 250 250 250 250 250 250 250 250 250 250 250 250 250Evaluation Water contact 105 112 109 105 104 95 100 110 110 104 103 10199 100 angle (°) PGMEA contact 55 53 54 56 52 45 50 56 57 54 57 56 52 53angle (°) Relative dielectric 2.7 2.7 2.7 2.7 2.7 2.9 2.9 2.5 2.5 2.62.6 2.7 2.7 2.7 constant Solvent ◯ ◯ ◯ ◯ ◯ ◯ ◯ Δ Δ Δ Δ Δ Δ Δ resistance

TABLE 3 Ex. 31 Ex. 32 Ex. 33 Ex. 34 Ex. 35 Ex. 36 Ex. 37 Ex. 38 Ex. 39Ex. 40 Ex. 41 Composition (A) A1 80 80 80 (parts by A2 60 60 60 60 mass)A3 60 60 60 60 (B) ADCP 20 40 40 ATMPT 20 40 40 M408 20 40 40 ADPH 40 40(C) C1 C2 0.5 0.5 C3 C4 C5 1 C6 5 0.5 0.5 C7 5 1 0.5 C8 1 0.5 (D2) OXE015 10 10 10 10 10 10 OXE02 5 5 5 5 Solvent PGMEA 250 250 250 250 250 250250 250 250 250 250 Evaluation Water contact angle (°) 96 94 95 99 96 9595 95 96 97 95 PGMEA contact angle 47 48 45 44 46 44 43 46 47 48 45 (°)Relative dielectric 2.6 2.6 2.6 2.9 2.9 2.9 2.9 2.9 2.9 2.9 2.9 constantSolvent resistance ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Ex. 42 Ex. 43 Ex. 44 Ex. 45 Ex.46 Ex. 47 Ex. 48 Ex. 49 Ex. 50 Composition (A) A1 100 100 100 100 (partsby A2 100 100 mass) A3 100 100 100 (B) ADCP ATMPT M408 ADPH (C) C1 1 C25 C3 5 C4 1 1 C5 1 C6 C7 C8 10 5 1 (D2) OXE01 10 10 10 5 OXE02 10 10 1010 10 Solvent PGMEA 250 250 250 250 250 250 250 250 250 Evaluation Watercontact angle (°) 96 94 98 97 98 97 105 100 95 PGMEA contact angle 50 4846 45 45 47 50 54 47 (°) Relative dielectric 2.5 2.5 2.5 2.5 2.6 2.6 2.72.7 2.7 constant Solvent resistance Δ Δ Δ Δ Δ Δ Δ Δ Δ

TABLE 4 Ex. 51 Ex. 52 Ex. 53 Ex. 54 Ex. 55 Ex. 56 Ex. 57 Ex. 58 Ex. 59Ex. 60 Composition (A) A3 60 60 60 60 60 60 60 60 60 60 (parts by (B)ADCP 40 mass) ATMPT 20 M408 40 40 40 40 40 40 40 40 20 (C) C9 2.5 C102.5 C11 2.5 C12 2.5 C13 2.5 2.5 2.5 C14 2.5 C15 2.5 C16 2.5 (D1) BPO 8 88 8 8 8 8 8 8 (D2) OXE01 10 Solvent PGMEA 250 250 250 250 250 250 250250 250 250 Evaluation Water contact angle (°) 85 104 103 101 93 80 8590 93 90 PGMEA contact angle 35 57 58 57 39 16 21 25 39 35 (°) Relativedielectric 2.9 2.9 2.9 2.9 2.9 2.9 2.9 2.9 2.9 2.9 constant Solventresistance ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯

As shown from the results in Table 1, in Examples 1, 2, 7 and 8 in whichthe prepolymer (A), the compound (B) and the radical polymerizationinitiator (D) were contained, a cured film excellent in the solventresistance was obtained.

Whereas, in Example 3 (thermal curing) in which the prepolymer (A) wascontained and neither of the compound (B) and the radical polymerizationinitiator (D) was contained, although a cured film was formed, the filmremaining ratio was 0. In Example 8 (photo-curing), curing did notproceed, and no cured film was formed.

Further, in Example 4 (thermal curing) in which no compound (B) wascontained although the prepolymer (A) and the radical polymerizationinitiator (D) were contained, although a cured film was formed, theswell ratio was so high as 10%, and the film remaining ratio was so lowas 80%. In Example 9 (photo-curing), the film remaining ratio was 100%,but the swell ratio was so high as 10.

Further, in a case where no radical polymerization initiator (D) wascontained even though the prepolymer (A) and the compound (B) werecontained, in Example 5 (thermal curing), although a cured film wasformed, the film remaining ratio was 0. In Example 10 (photo-curing),curing did not proceed, and no cured film was formed.

As shown from the results in Tables 2, 3 and 4, in Examples 11 to 17, 31to 41 and 51 to 60 in which the prepolymer (A), the compound (B), thecopolymer (C) and the radical polymerization initiator (D) werecontained, the solvent resistance of the cured film was favorable, andthe relative dielectric constant was low. Particularly in Examples 11 to17, 31 to 41 and 52 to 54, the water contact angle was at least 94° andthe PGMEA contact angle was at least 43°, and the water repellency andthe oil repellency on the surface of the cured film were excellent.

Further, in Examples 18 to 24 and 42 to 50 in which the prepolymer (A),the copolymer (C) and the radical polymerization initiator (D) werecontained and no compound (B) was contained, the relative dielectricconstant of the cured film was low, and the water repellency and the oilrepellency on the surface of the cured film were favorable, but thesolvent resistance of the cured film was poor.

Examples 71 to 78 and 81 to 85 Irradiation Test Using Mask PatternExamples 71 to 78

The surface of the cured film obtained in each of Examples 17 and 52 to58 was selectively irradiated with ultraviolet light by means of a maskpattern. Irradiation with ultraviolet light was carried out by usingSpot-Cure SP-7 (manufactured by USHIO INC.) under an irradiationcondition of 50 J/cm². Under this condition, light having a wavelengthof at most 200 nm is not applied.

With respect to a portion (irradiated portion) irradiated withultraviolet light and a portion (non-irradiated portion) which was notirradiated, the contact angles were measured by the above method. Theresults are shown in Table 5.

TABLE 5 Ex. Ex. 71 Ex. 72 Ex. 73 Ex. 74 Ex. 75 Ex. 76 Ex. 77 Ex. 78Curable composition Ex. 17 Ex. 52 Ex. 53 Ex. 54 Ex. 55 Ex. 56 Ex. 57 Ex.58 Water Before irradiation 100 104 103 101 93 80 85 90 contact AfterIrradiated 100 94 76 65 52 55 61 69 angle irradiation portion (°) Non-100 104 103 101 93 80 85 90 irradiated portion PGMEA Before irradiation50 57 58 57 39 16 21 25 contact After Irradiated 50 <10 <10 <10 <10 <10<10 <10 angle irradiation portion (°) Non- 50 57 58 57 39 16 21 25irradiated portion

In Example 71 in which the curable composition in Example 17 was used,the contact angles at the irradiated portion and non-irradiated portionafter irradiation with ultraviolet light were the same. Whereas inExamples 72 to 78 in which the curable compositions in Examples 52 to 58using the copolymer having units (c1) having a group which promotesdecomposition in the presence of light and/or ozone as the copolymer (C)were used, the contact angle at the irradiated portion after theirradiation with ultraviolet light was significantly decreased. That is,the irradiated portion had a lyophilic property and the non-reradiatedportion had liquid repellency. By using a mask pattern, a pattern of thelyophilic portion and the liquid repellent portion could be formed onthe surface of the cured film.

Examples 81 to 85

The surface of the cured film obtained in each of Examples 17, 52, 55,57 and 58 was selectively irradiated with ultraviolet light by means ofa mask pattern. Irradiation with ultraviolet light was carried out byusing a UV cleaning device UV-208 (manufactured by Technovision Inc.)under an irradiation condition of 900 mJ/cm². Under this condition,light having a wavelength of at most 200 nm is applied and ozone isgenerated.

With respect to the portion (irradiation portion) irradiated withultraviolet light and a portion (non-irradiated portion) which was notirradiated, the contact angles were measured by the above method. Theresults are shown in Table 6.

TABLE 6 Ex. Ex. 81 Ex. 82 Ex. 83 Ex. 84 Ex. 85 Curable composition Ex.17 Ex. 52 Ex. 55 Ex. 57 Ex. 58 Water Before irradiation 100 104 93 85 90contact After Irradiated 76 <10 <10 <10 <10 angle irradiation portion(°) Non- 100 104 93 85 90 irradiated portion PGMEA Before irradiation 5057 39 21 25 contact After Irradiated 31 <10 <10 <10 <10 angleirradiation portion (°) Non- 50 57 39 21 25 irradiated portion

In Example 81 in which the curable composition in Example 17 was used,the contact angle at the irradiated portion after irradiation withultraviolet light was decreased. In Examples 82 to 85 in which thecurable compositions in Examples 52, 55, 57 and 58 using the copolymerhaving units (c1-5) having a group which promotes decomposition in thepresence of light and/or ozone as the copolymer (C), were used, thecontact angle at the irradiated portion after the irradiation withultraviolet light was significantly decreased. That is, the irradiatedportion had a lyophilic property and the non-reradiated portion hadliquid repellency. By using a mask pattern, a pattern of the lyophilicportion and the liquid repellent portion could be formed on the surfaceof the cured film.

Accordingly, it is found that when the surface of a cured filmobtainable by curing the curable composition of the present invention isirradiated with ultraviolet light, the liquid repellency is lowered, andthe irradiated portion has a lyophilic property. The tendency how theliquid repellency is decreased varies depending on the irradiationconditions or the composition of the curable composition.

Examples 91 to 96 Preparation and Evaluation of Organic Thin-FilmTransistor Examples 91 Top Contact, Pentane

On a glass substrate, Al was deposited for 30 nm to form a gateelectrode. Then, the solution in Example 2 was applied by a spin coaterto form a film, which was heated on a hot plate at 90° C. for 10 minutesand at 150° C. for 30 minutes to form a gate insulating film for 200 nm.Then, on the gate insulating film, pentacene as an organic semiconductorwas vacuum-deposited to form a film for 30 nm, and Au was vacuumdeposited to form a film by means of a metal mask, thereby to form asource electrode and a drain electrode. The gate width was 1 mm, and thegate length was 50 μm.

Of the organic thin-film transistor thus prepared, the voltage-currentcharacteristics were measured in nitrogen at room temperature (from 20to 25° C.).

In FIG. 4, the gate voltage (VG)-drain current (ID) characteristics whenthe drain voltage (VD) is −30 V are shown. On that occasion, themobility (μ) was 0.09 cm²/Vs, and the threshold voltage (VTH) was −11 V.Sufficiently excellent characteristics as an organic transistor wereobtained.

The mobility (μ) is calculated by the following method.

The drain current (ID) is represented by the following formula:ID=WCμ(VG−VTH)²/2Lμ=(2L/WC)(ID/(VG−VTH)²)=(2L/WC)α²

W: channel width of transistor, C: capacitance of gate insulating film,VG: gate voltage, VTH: threshold voltage, a: slope of graph obtained byplotting square root of absolute value of drain current (ID) onlongitudinal axis and gate voltage (VG) on horizontal axis.

From these formulae, the mobility (μ) of an organic semiconductor can bedetermined from the slope of a graph obtained by plotting the squareroot of the absolute value of the drain current (ID) on the longitudinalaxis and the gate voltage (VG) on the horizontal axis.

Examples 92 Top Contact

An organic thin-film transistor was produced in the same manner as inExample 91 except that the solution in Example 17 was used as the gateinsulating film material.

In FIG. 5, the gate voltage (VG)-drain current (ID) characteristics whenthe drain voltage (VD) is −30 V are shown. On that occasion, themobility (μ) was 0.13 cm²/Vs, and the threshold voltage (VTH) was −5 V.Sufficiently excellent characteristics as an organic transistor wereobtained. It was confirmed that the organic thin-film transistor usingthe solution in Example 17 has a higher response speed, since themobility (μ) is higher than the mobility (μ) of the organic thin-filmtransistor in Example 91.

Examples 93 Bottom Contact

On a glass substrate, Al was vapor deposited for 30 nm to form a gateelectrode. Then, the solution in Example 2 was applied by a spin coaterto form a film, which was heated on a hot plate at 90° C. for 10 minutesand at 150° C. for 30 minutes to form a gate insulating film for 200 nm.Then, Au was vacuum-deposited to form a film by means of a metal mask,thereby to form a source electrode and a drain electrode, and further,pentacene as an organic semiconductor was vacuum deposited to form afilm for 50 μm. The gate width was 500 μm, and the gate length was 10μm.

Of the organic thin-film transistor produced in such a manner, thevoltage-current characteristics were measured in nitrogen at roomtemperature (from 20 to 25° C.).

In FIG. 6, the gate voltage (VG)-drain current (ID) characteristics whenthe drain voltage (VD) is −15 V are shown. On that occasion, themobility (μ) was 0.06 cm²/Vs, and the threshold voltage (VTH) was −3 V.Sufficiently excellent characteristics as an organic transistor wereobtained.

Examples 94 Bottom Contact

An organic thin-film transistor was produced in the same as in Example93 except that the solution in Example 17 was used as the gateinsulating film material.

In FIG. 7, the gate voltage (VG)-drain current (ID) characteristics whenthe drain voltage (VD) is −15 V are shown. On that occasion, themobility (μ) was 0.07 cm²/Vs, and the threshold voltage (VTH) was −3 V.Sufficiently excellent characteristics as an organic transistor wereobtained. Further, it was confirmed that the organic thin-filmtransistor using the solution in Example 17 had a higher response speed,since the mobility (μ) is higher than the mobility (μ) of the organicthin-film transistor in Example 93.

Examples 95 Bottom Contact

On a glass substrate, Al was vapor deposited for 30 nm to form a gateelectrode. Then, the solution in Example 2 was applied by a spin coaterto form a film, which was heated on a hot plate at 90° C. for 10 minutesand at 120° C. for 60 minutes to form a gate insulating film for 200 nm.Then, Au was vacuum-deposited to form a film by means of a metal mask,thereby to form a source electrode and a drain electrode, and further,PB16TTT as an organic semiconductor was formed into a film for 20 nm bydrop casting method. The gate width was 500 μm, and the gate length was10 μm.

Of the organic thin-film transistor produced in such a manner, thevoltage-current characteristics were measured in nitrogen at roomtemperature (from 20 to 25° C.).

In FIG. 8, the gate voltage (VG)-drain current (ID) characteristics whenthe drain voltage (VD) is −15 V are shown. On that occasion, themobility (μ) was 0.02 cm²/Vs, and the threshold voltage (VTH) was 9 V.Sufficiently excellent characteristics as an organic transistor wereobtained.

Examples 96 Bottom Contact

An organic thin-film transistor was produced in the same as in Example95 except that the solution in Example 17 was used as the gateinsulating film material.

In FIG. 9, the gate voltage (VG)-drain current (ID) characteristics whenthe drain voltage (VD) is −15 V are shown. On that occasion, themobility (μ) was 0.1 cm²/Vs, and the threshold voltage (VTH) was 1 V.Sufficiently excellent characteristics as an organic transistor wereobtained. Further, it was confirmed that the organic thin-filmtransistor using the solution in Example 17 had a higher response speed,since the mobility (μ) is higher than the mobility (μ) of the organicthin-film transistor in Example 95.

INDUSTRIAL APPLICABILITY

The cured film of the curable composition of the present invention isuseful as a functional film for semiconductor devices and other variouselectronic devices, and the like. Particularly, it is useful as aninsulating film of devices such as organic thin-film transistors, andthe curable composition of the present invention is used as a materialto produce such a functional film.

This application is a continuation of PCT Application No.PCT/JP2011/057699, filed on Mar. 28, 2011, which is based upon andclaims the benefit of priority from Japanese Patent Application No.2010-142828 filed on Jun. 23, 2010. The contents of those applicationsare incorporated herein by reference in its entirety.

REFERENCE SYMBOLS

-   -   1: Substrate    -   2: Gate electrode    -   3, 13: Gate insulating film    -   4, 14: Organic semiconductor layer    -   5, 15: Source electrode    -   6, 16: Drain electrode    -   13 a: Hydrophilic region    -   13 b: Liquid repellent region

What is claimed is:
 1. A curable composition comprising: a fluorinatedpolyarylene prepolymer (A) having a crosslinkable functional group; acompound (B) having a number average molecular weight of from 140 to5,000, having at least two crosslinkable functional groups and having nofluorine atoms; a copolymer (C) comprising units (c1) and (c2); and aradical polymerization initiator (D), wherein the unit (c1) has nocrosslinkable functional groups, and is a unit formed by polymerizationof a monomer represented by formula (5):V—(CH₂)_(m)—Ar—(Y—Ar)_(n)—X—R¹—Cf  (5) wherein V is a polymerizablegroup, Ar is an aromatic ring which may have a C₁₋₁₅ alkyl group or ahalogen atom, R¹ is a single bond or a C₁₋₁₅ alkylene group, Cf is afluoroalkyl group having at most 20 carbon atoms, which may have anetheric oxygen atom between carbon atoms, X is —CH₂O— or —COO— Y is asingle bond, —OCH₂—, —CH₂O—, a C₁₋₄ alkylene group, —O—, —OCH₂—, —CO—,—SO₂— or —S—, m is an integer of from 0 to 4, and n is 0 or 1; whereinthe unit (c2) has a crosslinkable functional group; and wherein thecurable composition comprises from 0.1 to 20 parts by mass of thecopolymer (C) based on 100 parts by mass of a total amount of theprepolymer (A) and the compound (B).
 2. The curable composition of claim1, wherein each of the crosslinkable functional groups in the prepolymer(A), the compound (B) and the compound (C) which are independent of oneanother, is a crosslinkable functional group selected from the groupconsisting of a vinyl group, an allyl group, an ethynyl group, avinyloxy group, an allyloxy group, an acryloyl group, an acryloyloxygroup, a methacryloyl group and a methacryloyloxy group.
 3. The curablecomposition of claim 1, comprising from 10 to 80 parts by mass of thecompound (B) based on 100 parts by mass of the total amount of theprepolymer (A) and the compound (B).
 4. The curable composition of claim1, wherein the radical polymerization initiator (D) is a thermalinitiator or a photoinitiator.
 5. A coating composition comprising thecurable composition of claim 1 and a solvent.
 6. A process for producingthe curable composition of claim 1, the process comprising: reacting afluorinated aromatic compound, a phenol compound and a crosslinkablefunctional group-comprising organic compound in the presence of adehydrohalogenating agent to produce the fluorinated polyaryleneprepolymer (A) having a crosslinkable functional group, and mixing thefluorinated polyarylene prepolymer (A), the compound (B) having a numberaverage molecular weight of from 140 to 5,000, having at least twocrosslinkable functional groups and having no fluorine atoms, thecopolymer (C) having the units (c1) and (c2), and the radicalpolymerization initiator (D) to obtain the curable composition.
 7. Aprocess for producing a cured film, the process comprising forming afilm of the coating composition of claim 5 on a substrate, and thermallycuring or photo-curing the curable composition by one or more heatingoperations to produce a cured film, wherein the heating temperature inall the heating operations is at most 250° C.
 8. A substrate comprisinga cured film of the curable composition of claim
 1. 9. A method fortreating a cured film, the method comprising irradiating a cured film ofthe curable composition of claim 1 with light, which lowers a liquidrepellency at a light-irradiated portion.
 10. An organic thin-filmtransistor comprising a cured film obtained by curing a film of thecurable composition of claim 1 as a functional film.
 11. The organicthin-film transistor of claim 10, wherein the functional film is a gateinsulating film.
 12. The curable composition of claim 1, wherein thecurable composition comprises from 0.1 to 10 parts by mass of thecopolymer (C) based on 100 parts by mass of a total amount of theprepolymer (A) and the compound (B).